Donald Trump has defended his hardline stance on immigration, a day after it was attacked by fellow Republican presidential candidates on national TV
His plan to deport the estimated 11 million people living illegally in the US was decried as impractical during an election debate in Wisconsin.
But he said on Wednesday it was cheap, "doable" and humane.
Democratic President Barack Obama wants to lift the threat of deportation to millions of undocumented people.
But his plan to allow about four million people to apply for work permits has been hindered by legal challenges.
Image copyrightAPImage caption Border Patrol agents in Texas Mr Trump, a billionaire New Yorker who has been leading in the polls, defended his plan to build a wall on the US-Mexico border and deport all the people living illegally in the US.
"You're going to have a deportation force, and you're going to do it humanely," he told MSNBC's Morning Joe.
"You have millions of people that are waiting in line to come into this country and they're waiting to come in legally." How do you deport 11m people? Debate exposes Republican divisions
He pointed to the actions of former US President Dwight Eisenhower, who authorised what was probably the largest deportation operations in US history.
What was Operation Wetback?
Sparked by post-war concerns about "invasion" of illegal labour from Mexico
Hundreds of immigration agents combed the SW in 1954 and 1955 searching for people without documents
More than a million people were taken, some transported deep into Mexican interior
Many died in the process
The term "wetback" is an offensive epithet for people living illegally in the US
Senator Ted Cruz backed Mr Trump during the debate, condemning any form of "amnesty" because illegal immigration kept wages low for American workers.
But his fellow Republican, Ohio Governor John Kasich, said that mass deportation was a "silly argument" that could never work and would split families.
The issue has exposed the diverging views within the party, and Florida Senator Marco Rubio clarified his stance on Wednesday.
He described his position as a "very long path" to citizenship when people had spent at least 10 years on a work permit.
President
Barack Obama is close to announcing major changes to the US immigration
system through executive action, US media report.
Reports in the New York Times and Fox News say Mr Obama is planning to extend protection from deportation to some parents of legal US residents.
The overall plan is estimated to affect as many as five million undocumented immigrants living in the US.
Republicans in Congress say such action would be beyond Mr Obama's authority.
"We're going to fight the president tooth and nail if he continues down this path," House Speaker John Boehner told reporters.
Mitch McConnell, the incoming Senate majority leader, urged
the president to "work with us to try to find a way to improve our
immigration system".
"The president has been told over and over and over again -
and we're telling him again today - don't do this because his executive
actions are not permanent changes," he said.
The president also faces pressures from within his own party.
Top Senate Democrat Harry Reid urged Mr Obama only to take action after
Congress passes a bill funding the government past 11 December.
"It's up to him," Mr Reid said. "But I'd like to get the finances of this country out of the way before he does it."
Some Republicans are pushing for the budget bill to include a
statement prohibiting "the use of appropriated funds for the
president's immigration machinations".
Such a move could provoke a block by the Democrats, or a veto
by the president, which in turn raises the risk of a government
shutdown.
The BBC travelled to California and Mexico, to report on US deportees
Unilateral action has been expected on immigration but details
of what the president was considering were first reported this week.
At the centre of the reports is a plan to extend the
president's "deferred action" plan, which was designed to protect young
adults who were brought to the US illegally as children from being
deported.
The plan is to extend that to the parents of children who are US citizens or legal residents.
The action is designed to prevent the break-up of families
via deportations. The number of those affected by the suggested policy
is based on how long an individual has lived in the US.
If the administration limits the "deferred action" to those
who have lived in the US for more than 10 years, it would affect 2.5
million undocumented immigrants, experts estimate.
Republicans say they want increased border security alongside immigration reform
If the time limit is lowered to five years, it would stop deportations for as many as 3.3 million.
Other parts of the executive action include:
increasing the number of high-tech workers allowed to live and work in the US
an expansion of the existing deferred action plans that would move the cut-off date for children arriving to 2010
shift border security resources to the US southern border, according to reports.
The Senate passed a far-reaching immigration bill in 2013, but the House has not taken up the legislation.
Stephanie Ramirez made the agonising decision to leave her family behind
White House press secretary Josh Earnest said the president would not take any executive action if Congress acts.
"If the House does pass the bipartisan Senate bill that's
already passed, the president would happily sign that into law," Mr
Earnest said.
"And if he has already made a decision and moved forward on
his own executive actions, he would happily retract those executive
actions so that we could implement the bipartisan Senate bill."
LOS REYES LA PAZ, Mexico -- Only hours after the
publication of an Associated Press story on his case Tuesday, the U.S.
government issued a humanitarian visa enabling the return of a Harvard
University student who broke immigration rules by taking his dying
mother to Mexico.
Dario Guerrero was born in
Mexico and moved with his family to California when he was 2. The Obama
administration granted him and hundreds of thousands of other young
immigrants a reprieve from deportation two years ago.
But these people can't leave the U.S. without government approval. And Guerrero's mother was dying of cancer.
Desperate
to save her, Guerrero took his mother to clinics in Mexico before
getting that approval. She died there in August, and he's been stuck
since then. The government denied his initial request to return, saying
he effectively deported himself by taking his mother across the border
before the paperwork was done on his approval request.
Guerrero
has been languishing since then at his grandparents' home outside
Mexico City, saying he's hoping for another chance to return home to his
family in California and complete his studies in Massachusetts.
Hours
after the AP explained his story, he got his answer: In a two-page
letter to his lawyer, the U.S. Citizenship and Immigration Service said
it has conditionally approved a 2-year parole for Guerrero, meaning he
can return without fear of deportation.
"He should be back in America in a few days," his attorney Alan Klein told the AP.
Since
his mother died in August, the film studies major stayed with his
grandparents in a gang-controlled suburb of Mexico City. His effort to
get a exemption from the rules was a long shot: Last year, the agency
approved only about a third of the humanitarian parole petitions it
received.
Agency officials declined to discuss
any details of Guerrero's case because it is ongoing. However,
spokesman Chris Bentley said earlier Tuesday that "immigration law is
complex; anyone considering taking an immigration action needs to
clearly understand the potential consequences of that action first."
Guerrero
told the AP that he had submitted two requests for fast-tracked
permission to leave while his mother's health declined at the family's
home in Long Beach, California, and was asked to more fully document his
mother's medical condition. He could have tried to plead his case in
person, but he left instead before getting an answer.
"My mom had a lot of ups and downs," he said. "The decision to actually leave was made overnight."
Miami-based
immigration attorney Ira Kurzban says it's not infrequent for
immigrants to lose their legal status by leaving the country without
permission. It happens when they go on cruise ships - thinking they
haven't really left the U.S. - or take off due to a family emergency.
Many discover only later that they can't return, or are barred for
entering for as much as 10 years.
"There's no question (Guerrero) didn't follow the rules. The question is what the penalty should be," Kurzban said.
Any
immigrants with pending cases need permission to go abroad, which is
not difficult to get eventually, if their requests are deemed valid. But
those who don't wait for sometimes slow responses are considered to
have voluntarily given up their effort to remain in the U.S.
Advocates
say it should be easier for immigrants who have lived in the U.S. for
many years to get permission to travel. Visas for skilled H-1B temporary
workers already allow travel internationally without preapproval, and
giving others this freedom would reduce heartbreak and add only minimal
administrative work, Kurzban said.
But no such
provisions were included in last year's immigration reform bills, and
they aren't expected to be included in any executive action President
Barack Obama might announce later this year. Kurzban thinks that's
because the issue affects a relatively small group, and there are so
many other priorities.
When Rocio Meneses Diaz
died Aug. 14 at the age of 41 in the central Mexican state of
Guanajuato. Guerrero's 16-year-old brother also was by her side. As a
U.S.-born citizen, he is allowed to travel freely. Their father, a
building contractor in the U.S. illegally, stayed behind with their
9-year-old sister, also a citizen.
Guerrero
says he regrets his rash decision most of all because he thinks his
mother would have been happier living her final days in Southern
California with her husband and children, "but then we still had hope -
and if we delayed that treatment any longer because of immigration
issues, I don't think I would have been able to forgive myself."
Guerrero's
parents had kept his immigration status secret for years. They came
clean only when he began taking community-college engineering classes
while still in high school, and the Social Security number his parents
submitted bounced back.
Before her death,
Guerrero's mom opened up about the past and her reasons for leaving
Mexico: Her father had been kidnapped twice; her father-in-law and other
relatives faced extortion; armed thieves broke into her clothing and
jewelry store, holding a knife to her stomach.
Guerrero recorded her stories and her struggle with kidney cancer, hoping to turn it into a documentary back at school.
Instead,
he has passed time in a room next to a garage just big enough to fit
his twin bed and bureau. A picture of his mother and a single rose hang
above the bed. His grandparents rent out the nearest bathroom during
weekends for a pop-up street market. Guerrero sees his cousins after
they get off work, and "writes poetry and stuff" at night.
Former
Harvard lecturer Eoin Cannon, who taught history to Guerrero, was
surprised to learn of his student's predicament. Cannon described him as
"one of the most thoughtful and creative and original students that I
had the pleasure of teaching," and "an exceptional writer." Guerrero
tackled homelessness in a student film, and later co-produced "A Dream
Deferred," a documentary about other immigrants like himself at Harvard.
"He's
as American as anyone I know," Cannon said. "The law needs to sort of
recognize that and have a mechanism for accounting for that ... For the
law not to be able to handle his kind of case is hurting America."
Guerrero
says it's been liberating to have no term-paper deadlines to worry
about, but the lack of a routine keeps him edgy. He watches his back
when he ventures outside. Crime cartels have moved in, extorting
neighborhood businesses. Weeks ago, a relative was mugged and shot in
the stomach.
Harvard has been supportive,
granting him leave and helping him find sympathetic ears in Washington,
including Sen. Dick Durbin, an Illinois Democrat. But when asked what's
hardest about being stuck in Mexico, he loses his bravado and his voice
drops to a whisper: "That I don't have a mom anymore."
A Cuban spy on probation after 13 years behind bars in the United States can remain in Cuba, where he returned on a court-approved visit last month, if he renounces his U.S. citizenship, a federal judge in Miami ruled on Friday.
Rene Gonzalez, 56, one of what Cuba calls its "Five Heroes," returned to the communist island temporarily on April 22 to attend a memorial service for his deceased father.
U.S. District Judge Joan Lenard granted Gonzalez's request for the visit on condition that he return to Florida by next Monday.
In her ruling Friday, however, she said the U.S. government had raised no objection to a subsequent motion filed by Gonzalez's lawyer saying he would formally renounce his U.S. citizenship if he was allowed to serve out the remainder of his probation in Cuba.
The judge ordered that Gonzalez has until May 16 to obtain a "certificate of loss of nationality" from the U.S. State Department. If he failed to do so he would be required to return to the United States to complete his probation, she wrote.
The Chicago-born Gonzalez, who holds dual U.S.-Cuban citizenship, had first made the offer to drop his U.S. citizenship early last year, his lawyer said.
"If defendant voluntarily renounces his United States citizenship ... then defendant shall serve the remainder of his supervised-release term in Cuba on a non-reporting basis, and shall not return to the United States," Lenard wrote.
Gonzalez could not be reached for immediate comment. But his U.S. attorney, Philip Horowitz, said his client was happy with the judge's decision.
"It took a long time but the government finally accepted his offer," Horowitz said. "The government has made it very clear they don't want him to be a U.S. citizen," he added.
Lenard had also granted Gonzalez's request to visit a critically ill brother in Cuba in March of last year. Gonzalez returned to the United States after that visit.
Similarly, jailed American contractor Alan Gross has requested that Cuban President Raul Castro allow him a temporary return to the United States to visit his mother, who has inoperable lung cancer.
Gonzalez was convicted in 2001 of conspiring to spy on Cuban exile groups and U.S. military activities in Florida as part of an espionage ring known as the "Wasp Network."
One of his co-defendants is serving a double life sentence for his part in the shooting down of two U.S. planes in 1996 flown by an exile group that dropped anti-government leaflets over Havana.
The case of the so-called Cuban Five is little known outside the Cuban exile community in the United States but is a major issue in Cuba where the government repeatedly says they were wrongly convicted and demands their release.
Havana maintains the agents were only collecting information on Cuban exile groups planning actions against the island 90 miles from Key West, Florida.
Gonzalez was the first of the five to be released from jail when he finished his sentence in 2011, but he was ordered to stay in the United States for a three-year probation period that ends in October of next year.
Cuba has hinted at a possible swap of the Cuban Five for Gross, who is serving a 15-year sentence in Cuba for illegally installing Internet networks for Cuban Jewish groups. He was working for a U.S. program that Cuba considers subversive.
The United States has rejected the idea of any possible swap, however.
A Cuban spy on probation after 13 years behind bars in the United States can remain in Cuba, where he returned on a court-approved visit last month, if he renounces his U.S. citizenship, a federal judge in Miami ruled on Friday.
Rene Gonzalez, 56, one of what Cuba calls its "Five Heroes," returned to the communist island temporarily on April 22 to attend a memorial service for his deceased father.
U.S. District Judge Joan Lenard granted Gonzalez's request for the visit on condition that he return to Florida by next Monday.
In her ruling Friday, however, she said the U.S. government had raised no objection to a subsequent motion filed by Gonzalez's lawyer saying he would formally renounce his U.S. citizenship if he was allowed to serve out the remainder of his probation in Cuba.
The judge ordered that Gonzalez has until May 16 to obtain a "certificate of loss of nationality" from the U.S. State Department. If he failed to do so he would be required to return to the United States to complete his probation, she wrote.
The Chicago-born Gonzalez, who holds dual U.S.-Cuban citizenship, had first made the offer to drop his U.S. citizenship early last year, his lawyer said.
"If defendant voluntarily renounces his United States citizenship ... then defendant shall serve the remainder of his supervised-release term in Cuba on a non-reporting basis, and shall not return to the United States," Lenard wrote.
Gonzalez could not be reached for immediate comment. But his U.S. attorney, Philip Horowitz, said his client was happy with the judge's decision.
"It took a long time but the government finally accepted his offer," Horowitz said. "The government has made it very clear they don't want him to be a U.S. citizen," he added.
Lenard had also granted Gonzalez's request to visit a critically ill brother in Cuba in March of last year. Gonzalez returned to the United States after that visit.
Similarly, jailed American contractor Alan Gross has requested that Cuban President Raul Castro allow him a temporary return to the United States to visit his mother, who has inoperable lung cancer.
Gonzalez was convicted in 2001 of conspiring to spy on Cuban exile groups and U.S. military activities in Florida as part of an espionage ring known as the "Wasp Network."
One of his co-defendants is serving a double life sentence for his part in the shooting down of two U.S. planes in 1996 flown by an exile group that dropped anti-government leaflets over Havana.
The case of the so-called Cuban Five is little known outside the Cuban exile community in the United States but is a major issue in Cuba where the government repeatedly says they were wrongly convicted and demands their release.
Havana maintains the agents were only collecting information on Cuban exile groups planning actions against the island 90 miles from Key West, Florida.
Gonzalez was the first of the five to be released from jail when he finished his sentence in 2011, but he was ordered to stay in the United States for a three-year probation period that ends in October of next year.
Cuba has hinted at a possible swap of the Cuban Five for Gross, who is serving a 15-year sentence in Cuba for illegally installing Internet networks for Cuban Jewish groups. He was working for a U.S. program that Cuba considers subversive.
The United States has rejected the idea of any possible swap, however.
Image copyright AP 
