Russia has said it is returning more troops and weapons to bases, but Nato declared it saw no sign of a drawdown as fears that Moscow could invade Ukraine soon persisted.
Russia has massed about 150,000 troops east, north and south of Ukraine, sparking Western concerns it was planning an attack.
Moscow denies it has any such plans and this week said it was pulling back some forces and weapons, though it gave few details.
Those claims have been met with scepticism from the US and its allies — even as they seemed to lower the temperature following weeks of escalating East-West tensions.
On Wednesday, the Russian Defence Ministry released a video showing a trainload of armoured vehicles moving across a bridge away from Crimea, the Black Sea peninsula that Russia annexed from Ukraine in 2014.
A day earlier, the ministry reported the start of a pullback of troops following military exercises near Ukraine.
But Nato secretary-general Jens Stoltenberg threw cold water on those statements, saying the military organisation does not see any sign that Moscow is decreasing its troop levels around Ukraine.
“At the moment, we have not seen any withdrawal of Russian forces,” he said, before chairing a meeting of Nato defence ministers in Brussels.
“If they really start to withdraw forces, that’s something we will welcome but that remains to be seen.”
Countries in the alliance have also expressed doubt, as have leaders in Ukraine. Caught between Russia and the West, Ukrainian leaders have repeatedly sought to project calm but also strength during the crisis.
Negotiations
Meanwhile, the European Union’s senior diplomat has told the European Parliament that negotiations must continue with Russia while preparing its ability to respond in case of an invasion of Ukraine.
High Representative of the European Union for foreign affairs and security policy Josep Borrell told MEPs in Strasbourg on Wednesday that it was important to continue to participate in negotiations while also preparing the EU’s capacity to respond in the event of an invasion.
“We don’t know what Putin is going to do. But what is clear is that we have to continue offering both,” he said.
“We’re looking at sanctions and these are being drafted together with the help of the European Commission… and obviously these will come into play if Russia invades Ukraine.”
Mr Borell said that while the EU was "ready to act" with sanctions against Russia, diplomatic negotiations should continue, "in order to look for a diplomatic solution to the worst crisis that Europe is living in since the end of the Cold War".
President of the European Commission, Ursula von der Leyen, told the Parliament that Russia had sent “conflicting signals” over Ukraine.
“I truly hope the Kremlin will decide not to unleash further violence in Europe… But let’s stay vigilant. Despite yesterday’s news, Nato has not yet seen signs of any Russian troop reduction. Should the Kremlin choose violence, our response will be strong and united,” she said.
“Diplomacy has not yet spoken its last words and we saw signs of hope yesterday, but now deeds have to follow those words.”
She said the EU “must diversify our energy sources and must get rid of our dependency on Russian gas.”
“They are clean and good for the climate, but they are also home-grown and good for our independence. That’s where our future lies.”
Nato defence ministers are set to meet on Wednesday in Brussels to discuss how to respond to the crisis, which has been described as one of the worst in Europe since the end of the Cold War.
The European Commission this week set out proposals to increase co-operation between EU members on defence, including with VAT incentives to encourage joint purchasing of military equipment to ensure good value and interoperability.
‘Threatening position’
On Tuesday, Joe Biden has claimed that 150,000 Russian troops remain in a "threatening position" around Ukraine, despite Russian claims of a withdrawal, and warned that an invasion "remains distinctly possible".
In a televised address from the White House, Mr Biden combined a repeated offer of security talks with a warning of severe repercussions if Russia carries out an attack that US intelligence has reportedly assessed could take place as early as Wednesday.
In his speech, Mr Biden said he would “rally the world” to oppose Russian military action but made clear that the response would be primarily economic, saying: “I will not send American servicemen to fight in Ukraine.”
But he made clear that any attack on Nato territory or harm to Americans would be treated differently.
"We're not seeking direct confrontation with Russia, though I've been clear that if Russia targets Americans and Ukraine, we will respond forcefully," Mr Biden said. "If Russia attacks the United States or our allies through asymmetric means, like disruptive cyber-attacks against our companies or critical infrastructure, we're prepared to respond."
In his televised address, Mr Biden made clear the US was unconvinced by the Kremlin’s claims of a withdrawal.
"We have not yet verified that Russian military units are returning to their home bases. Indeed our analysts indicate that they remain very much in a threatening position," the president said. "The fact remains right now Russia has more than 150,000 troops encircling Ukraine and Belarus and along Ukraine's border. An invasion remains distinctly possible."
Russia has always denied planning to invade Ukraine, saying it can exercise troops on its own territory as it sees fit. It has been pressing for a set of security guarantees from the west, including a guarantee that Ukraine will never join Nato. – Additional reporting from Guardian/AP
