WASHINGTON — US President Joe Biden on Friday pledged to make it “very, very difficult” for Russia's Vladimir Putin to take military action in Ukraine and said new initiatives coming from his administration are intended to deter Russian aggression.

“What I am doing is putting together what I believe to be will be the most comprehensive and meaningful set of initiatives to make it very, very difficult for Putin to go ahead and do what people are worried he may do,” Biden told reporters.

Keiv and Washington accuse Moscow of massing tens of thousands of troops on the border and of drawing up plans to invade.

The Kremlin said earlier that President Putin would seek binding guarantees precluding NATO’s expansion to Ukraine during a planned call with his US counterpart.

There are signs that Washington and Moscow are close to arranging a conversation next week.

Ukraine is refusing to give up its aim to join NATO, as well as give any "security guarantee" to Russia, the country's foreign minister said on Friday.

Dmytro Kuleba also told AFP he wanted other Western nations to do the same. He called on the United States and its North Atlantic allies to reject Moscow's demands for easing tensions along the Russia-Ukraine border.

"I reject this idea that we should guarantee anything to Russia. I insist: it's Russia which should guarantee that it will not continue its aggression against any country," he said, speaking on the sidelines of the OSCE summit in Stockholm.

An agreement by Ukraine to abandon its goal of joining NATO "is not an option", Kuleba said, stressing that NATO and EU membership are in the Ukrainian constitution.

The minister added that it was "absolutely inappropriate" for Russia to exert any influence on decisions taken by a sovereign country like Ukraine, or an international organization like NATO.

Ukraine's defense minister told parliament on Friday the number of Russian troops in the area was estimated to be 94,300. Oleksii Reznikov said intelligence suggested a "probability of a large-scale escalation" by Russia in late January.

He added that Ukraine would not do anything to provoke Russia but is prepared to respond in case of an attack.

Moscow has warned that any presence of NATO troops and weapons on Ukrainian soil represents a "red line". The Kremlin says it is concerned that Keiv might use force to reclaim control of the country's rebel east.

This week has seen a war of words between all three capitals over the rising tensions.

US Secretary of State Antony Blinken told Euronews that Washington would "respond" if Russia acted "recklessly" over Ukraine. The West has threatened the Kremlin with the toughest sanctions yet if it launches an invasion of Ukraine.

Moscow has insisted it has no such intention and accused Ukraine and its Western backers of making up the claims to cover up their own allegedly aggressive motives.

Russia's Foreign Minister Sergei Lavrov, who met Blinken in Stockholm, warned NATO against deploying its troops and weapons to Ukraine.

The top Russian diplomat charged the West was "playing with fire" when turning Ukraine "into a bridgehead for confrontation".

The current tensions over Ukraine come seven years after Russia's annexation of Crimea and the takeover of part of eastern Ukraine by pro-Russian separatists. — Euronews