A gunman wearing a business suit opened fire at Russia's ambassador Andrei Karlov.
Turkey on Monday said it would not allow the assassination of the Russian ambassador to Ankara to damage relations with Moscow, describing the killing as a "terror attack" on bilateral relations.
"We will not allow this attack to cast a shadow on Turkey-Russia relations," said the Turkish foreign ministry in a statement. Interior Minister Suleyman Soylu said the killing of Andrei Karlov was "a terror attack on relations between Russia and Turkey".
A gunman wearing a black-and-white business suit and tie opened fire on Monday at Russia's ambassador, killing the diplomat and wounding several others at an art gallery in Ankara, officials said.
As screams rang out, the gunman could then be seen pacing about and shouting as he held the gun in one hand and waved the other in the air.
A video showed the attacker shouting: "Don't forget Aleppo, don't forget Syria!"
Two security sources identified the gunman as an off-duty police officer who worked in the Turkish capital. The gunman was later killed as panicked people scattered for cover in the gallery.
Russia and Turkey have both been involved in the conflict in Syria, which borders Turkey. Turkey has been a staunch opponent of Assad, while Russia has deployed troops and its air force in support of the Syrian leader.
The US State Department, involved in diplomatic contacts with Russia in an attempt to resolve a refugee crisis unfolding around the city of Aleppo, condemned the attack.
(with inputs from agencies)