MOSCOW: The Kremlin said Wednesday it was "positive" that US President Joe Biden wanted to continue talks on the Ukraine crisis, as Moscow said it was pulling back some troops from its neighbour's border.

"It is positive that the US president is also noting his readiness to start serious negotiations," Kremlin spokesman Dmitry Peskov told reporters.

A day earlier Biden had vowed to push for a diplomatic solution to the crisis.

But he also warned that a Russian invasion remained "very much a possibility" and that retaliatory sanctions were primed and ready.

Biden and Putin to speak as Ukraine warnings mount

"We can welcome that the president of the United States, one of the most powerful countries, thinks about the Russian nation," Peskov said.

"Of course, we would rather not hear the threats about what will happen to us if we do something or not do something," he added.

"We are tired of these threats."

The Kremlin spokesman said negotiations would be "very complex and will require flexibility on both sides".

Russia this week announced the end of some of its massive military drills on Ukraine's borders.

But Biden said that despite Russian claims, Washington and its allies had yet to verify the withdrawal of any of the 100,000 troops he says Moscow has now mustered along Ukraine's border.