The head of the US Central Intelligence Service, William Burns, has met with the head of the Russian Foreign Intelligence Service, Sergei Naryshkin, in Ankara, the capital of Turkey, Vladimir Putin's spokesman Dmitry Peskov on Monday confirmed to the Russian government media TASS.

Reuters also said this information was confirmed anonymously by one of the spokesmen of the White House before the meeting.

It cited the source as saying that the meeting concerned the threats of using nuclear weapons:

"He [Burns] is not negotiating. He does not discuss the issue of settling the war in Ukraine. [Burns] will deliver a message on the consequences of Russia's use of nuclear weapons and the risks of escalation to strategic stability ... He will also address the cases of wrongfully detained US citizens," said the source.

According to him, the USA had informed Ukraine about the meeting in advance.

"We firmly adhere to the fundamental principle: nothing about Ukraine, without Ukraine," he said.

This is the first known face-to-face meeting between high-ranking Russian and US officials since the Russian invasion of Ukraine.