Russia will not hand back control of Crimea to Ukraine, Russia's foreign ministry said on Wednesday, responding to comments from the White House that the United States expected the Black Sea peninsula to be returned.
"We don't give back our own territory. Crimea is territory belonging to the Russian Federation," Maria Zakharova, spokeswoman for the Russian Foreign Ministry, told a news briefing.
On Tuesday, the White House said U.S. President Donald Trump had made it clear that he expects Russia to relinquish control of the territory.
Russia annexed Crimea in 2014, prompting the United States and the European Union to impose sanctions on Russia, plunging Western relations with the Kremlin to their worst level since the end of the Cold War.
"Terrorism will not pass! We will fight it resolutely," said ministry spokeswoman Maria Zakharova.
"The memory of this outstanding Russian diplomat, a man who did so much to counter terrorism... will remain in our hearts forever," she said.
US state department spokesman John Kirby said US officials were aware of reports about the attack on the ambassador.
"We condemn this act of violence, whatever its source," he said. "Our thoughts and prayers are with him and his family."
Video of the event shows Mr Karlov making a speech when gunshots ring out.
Image copyrightAPImage captionThe attacker shouted about Aleppo and SyriaImage copyrightBURHAN OZBILICIImage captionPeople crouched in the exhibition room after the shootingImage copyrightREUTERSImage captionPolice secured the area after the shooting
The camera pulls back to show a smartly dressed gunman, wearing a suit and tie, waving a pistol and shouting.
He can be heard yelling "Don't forget about Aleppo, don't forget about Syria" and uses the Arabic phrase "Allahu Akbar" (God is great).
While there were protests in recent days about the situation in Aleppo, on a political level the Turkish and Russian governments have been co-operating in the ceasefire operation, the BBC's Turkey correspondent, Mark Lowen, reports.
It is too early to know the motives of the attacker, who has not yet been named. Some reports say he entered the art gallery using a police ID card, our correspondent adds.
