Russia on Thursday announced more troop pullbacks from the Ukrainian border as Washington insisted that Moscow is still building up forces for a potential invasion of its pro-Western neighbor.
After previously announced withdrawals earlier this week, the United States, NATO and Ukraine all said they had seen no evidence of a pullback.
The Russian Defense Ministry said units of the southern military district were returning to bases from Moscow-annexed Crimea and that tank units of the western military district had departed on a military train for their bases 1,000 kilometers (620 miles) away.
It did not provide details on the specific amount of troops or equipment involved.
Western officials say Russia has amassed well over 100,000 troops and significant military hardware near Ukraine's borders in preparation for a potential invasion, which Washington says could take place "at any time."
Russia has said "large-scale" military exercises are taking place in various areas, including near Ukraine, but has not provided any specific numbers and has repeatedly denied any plans for an attack.
U.S. says pullback claims 'false'
The troop build-up and Western threats to respond to an invasion with painful economic sanctions have brought tensions between Moscow and the West to their highest since the end of the Cold War.
Intense diplomatic efforts — including meetings and repeated phone calls between President Vladimir Putin and Western leaders — have done little to ease the crisis.
British Foreign Secretary Liz Truss, who was due in Kyiv on Thursday warned that the crisis risked becoming "a running sore."
Moscow "could drag this out much longer in a brazen ploy to spend weeks more — if not months — subverting Ukraine and challenging Western unity," she wrote in the Daily Telegraph.
A senior White House official on Wednesday said Russian announcements of withdrawal were "false," accusing Moscow of increasing its presence on the border by "as many as 7,000 troops."
NATO chief Jens Stoltenberg and other Western officials also said they saw no sign of a drawdown, and Ukrainian President Volodymyr Zelenskiy said Kyiv had observed only "small rotations" that did not signify any real change.
Presiding over a national "Day of Unity" he declared on Wednesday, Zelenskiy watched Ukrainian soldiers train with new Western-supplied anti-tank weapons and visited the frontline city of Mariupol.
"We are not afraid of anyone, of any enemies," Zelenskiy said. "We will defend ourselves."
Russian officials have accused the West of provoking "hysteria" with claims of a planned invasion.
Even Ukrainian officials have warned that some Western moves — including the U.S. relocating its embassy from Kyiv to the western city of Lviv — are unjustified and helping to spread panic.
'Ukraine just a field of battle'
At the border of Ukraine and Belarus — where Russian and Belarusian forces are carrying out major joint exercises — residents feared being caught in the middle of a clash of great powers.
"The Ukrainians could start something, thanks to the Americans and the British, who brought all their weapons here," 87-year-old Lidiya Silina told AFP in her green wooden shack close to the border.
"For them, Ukraine is just a field of battle with Russia."
The joint drills in Belarus — which the U.S. says involves some 30,000 Russian troops — are set to end on Sunday.
Russia insists its forces will go back to bases after the exercises so a significant withdrawal early next week could set the stage for the crisis to ease.
Russia has blamed the West for provoking the tensions, saying Washington and its European allies have for too long ignored Moscow's security concerns on its doorstep.
Putin has demanded that Ukraine be forever banned from fulfilling its hopes of joining NATO and for the alliance to roll back its deployments near Russia's borders.
Russian Foreign Minister Sergei Lavrov said Thursday that Moscow would send a reply to U.S. proposals about European security later in the day.
European Union leaders, already gathered in Brussels for a summit with their African counterparts, were to hold impromptu crisis talks Thursday on Russia and Ukraine.
A UN Security Council meeting is also set Thursday to discuss the crisis.
U.S. Vice President Kamala Harris will also meet with Zelenskiy on the sidelines of the annual Munich Security Conference this weekend, a senior White House official said.