The leaders of Turkey and France attempted to mediate in the Ukraine crisis on Thursday as Washington announced it had evidence of a Russian plan to fake a Ukrainian attack to justify invading its neighbour.

The shock claim from the US came as Russia accused Washington of "escalating tensions" by sending 3,000 troops to eastern Europe to counter a massive build-up of Russian troops near Ukraine's border.

Western powers have been engaged in intense diplomatic efforts to try deter a feared Russian invasion of Ukraine.

French President Emmanuel Macron held telephone talks Thursday both with Russian President Vladimir Putin and his Ukrainian counterpart Volodymyr Zelensky to try defuse tensions.

Turkish President Recep Tayyip also sought to play the intermediary, offering on a visit to Kyiv to hold a Ukraine-Russia peace summit.

The scramble to head off another conflict in Ukraine comes eight years after Russia annexed the Crimea peninsula and Russian-backed separatists in Ukraine's east rose up against the pro-Western government in Kyiv.

The drama continued on Thursday with the Pentagon saying it had evidence of a plan by Moscow to film a fake Ukrainian attack on Russians to justify a real assault on its pro-West neighbour.

"As part of this fake attack, we believe that Russia would produce a very graphic propaganda video, which would include corpses and actors that would be depicting mourners and images of destroyed locations," he said, adding that the attack would target "Russian sovereign territory" or "Russian speaking people".

The latter could refer to the sizeable Russian-speaking population inside Ukraine.

Russia has denied any plans to attack Ukraine, saying the troops in the border area are carrying out military exercises.

In his third call in a week with Macron, Putin accused Kyiv of "provocative statements and actions" and stressed Russia's demand for security guarantees, alluding to Russia's call for NATO to halt its eastward expansion.

Ukraine's leader Zelensky said his discussions with Macron focused on the festering conflict in the breakaway regions of eastern Ukraine

"Agreed on further joint steps to maintain Ukraine's stability," he said on Twitter.

Erdogan also sought to act as go-between between Russia and Ukraine.

Western powers have been engaged in intense efforts to deter what they fear to be a looming invasion of Ukraine
Western powers have been engaged in intense efforts to deter what they fear to be a looming invasion of Ukraine AFP / Anatolii STEPANOV

But Russia is angry over NATO member Turkey's supply of combat drones to Kyiv.

Amid the diplomatic flurry, Washington angered Moscow by announcing the new troop deployments to two of NATO's eastern members on Wednesday.

US President Joe Biden said he was sending 2,000 troops to Poland and 1,000 to Romania to "reassure our NATO allies in eastern Europe that we're there".

The Kremlin urged the US to "stop escalating tensions" and Deputy Foreign Minister Alexander Grushko warned the "destructive" move would make it harder for a compromise between the two sides.

Pentagon spokesman John Kirby stressed that no US soldiers would be sent to fight in Ukraine.

But that is unlikely to assuage Putin, who has accused the United States and NATO of seeking to "contain" Russia by placing troops and strategic arms on its border.

Putin has demanded guarantees that Ukraine will not join NATO.

Russia also wants NATO and the United States to foreswear the deployment of missile systems near Russia's borders and to pull back NATO forces in eastern Europe.

Putin has left the door open to talks, saying he was studying Western proposals set out last month in response to Russia's demands, and that he hoped for a "solution".

The Kremlin also claimed it had China's support in the standoff -- backing that will be demonstrated when Putin meets President Xi Jinping in Beijing on Friday at the opening of the Olympics.

Ukraine's Defence Minister Oleksiy Reznikov insisted Thursday that "the probability of a significant escalation as of today is considered low" as Kyiv had not seen Moscow move "strike groups" to the border.

But tensions have been aggravated by plans for joint military exercises between Russia and neighbouring Belarus, where Washington claims Moscow is preparing to send 30,000 troops.