Nato has issued a warning to Russia over its “large and unusual” military build-up on the border with its former Soviet neighbour Ukraine and urged President Putin to make clear his intentions.
Jens Stoltenberg, Secretary General of the western military alliance, appealed for a de-escalation in tension as Russia massed troops, tanks and missiles at the frontier.
“We call on Russia to be transparent about its military activities. It is important to prevent escalations and reduce tensions,” he said.
His comments came after he held talks in Brussels with Dmytro Kuleba, the Ukrainian Foreign Minister, amid growing speculation that Russia is planning to invade its neighbour.
Ukraine’s Defence Ministry claims that about 90,000 Russian troops are stationed not far from the border in areas controlled by separatists in the eastern Donbass region.
It said units of the Russian 41st Combined Arms Army have remained in Yelnya, a town about 260 kilometres north of the Ukrainian border.
Videos and pictures posted on social media showed Russian troops and military vehicles moving towards Ukrainian territory.
It comes amid speculation that Russia is helping its ally Belarus to orchestrate a migrant crisis on the EU's borders as a distraction tactic.
Britain has accused Belarus’s authoritarian President Alexander Lukashenko of an “abhorrent” attempt to engineer the situation in an effort to undermine European unity.
Prime Minister Boris Johnson criticised the “contrived crisis” and said the UK stands “shoulder to shoulder” with its European allies as EU foreign ministers considered fresh sanctions against the regime in Minsk.
Two Ukrainian soldiers were on Friday killed when an explosive device detonated in the eastern part of the country.
The US has warned the EU to be wary of Russia’s intensions but diplomats for the bloc say that while they take note of the military build-up, they do not believe an all-out ground assault is planned.
Mr Stoltenberg highlighted past instances in which Russia had massed soldiers and military hardware on the 1,426 mile border, causing concern for Kiev and its international allies.
But he stopped short of suggesting Moscow might be preparing to invade and said Nato’s 30 member states should be realistic about the magnitude of the situation.
“What we see is a significant, large Russian military build-up. We see an unusual concentration of troops,” he said.
“And we know that Russia has been willing to use these types of military capabilities before to conduct aggressive actions against Ukraine.
“I think it’s important also that we don’t now increase tensions but we have to be clear-eyed, we need to be realistic about the challenges we face."
Conflict in Ukraine
Mr Kuleba called on Nato “to strengthen the resilience of Ukraine” and said, “we have to be ready for all scenarios, for all options”.
In a joint statement, the foreign ministers of Germany and France warned Russia against military action in Ukraine.
Heiko Maas and Jean-Yves Le Drian also urged Ukraine “to maintain a posture of restraint” and said they regret Russia’s refusal to meet them under the “Normandy format”, a reference to the group that France, Germany, Russia and Ukraine formed to settle the long-running conflict.
“Against the backdrop of renewed concerns about Russian movement of troops and hardware near Ukraine, we call on Russia to adopt a posture of restraint and provide transparent information about its military activities. Any new attempt to undermine Ukraine’s territorial integrity would have serious consequences,” the ministers said.
The armed conflict in the Donbass region of eastern Ukraine started in 2014.
Russia was accused by the international community of orchestrating an uprising of separatists in the eastern region and annexed Ukraine’s Crimean Peninsula the same year.
Seven years on, Russia-backed separatists control the Donbass territory and are engaged in combat with Ukrainian soldiers.
Earlier this year, Kiev claimed that its bigger and more powerful neighbour had massed troops on the border and appealed to Nato for assistance.