United States President Joe Biden said Friday he will soon send a small number of US troops to bolster the NATO presence in Eastern Europe as tensions rise over Russia's military buildup on the borders of Ukraine.
"I’ll be moving troops to Eastern Europe and the NATO countries in the near term. Not too many," Mr Biden told reporters on return to Washington from a speech in Philadelphia.
The United States already has tens of thousands of troops stationed across mostly Western Europe, but the Pentagon is discussing sending a small number of reinforcements to the tense eastern flank.
This week, spokesman John Kirby said 8,500 troops were on "heightened alert" for possible deployment to assist NATO.
The deployment would be as much politically as militarily significant, bolstering US involvement in the brewing conflict.
Ukraine is not a member of NATO, but Washington fears spillover into neighboring NATO countries if Russia attacks Ukraine.
Moscow insists it does not plan to attack but has stationed more than 100,000 combat troops on the borders and is demanding that Western powers exclude Ukraine from ever joining the NATO alliance, as well as other concessions.
Mr Biden warned in a press conference last week that a Russian assault on Ukraine would achieve the opposite of the Kremlin's stated goal.
"We’re going to actually increase troop presence in Poland, in Romania, etcetera if in fact, he moves," Mr Biden said. "They are part of NATO."
British Prime Minister Boris Johnson will speak to Russian President Vladimir Putin this week, urging him to step back from escalating tensions over Ukraine, Downing Street said Friday.
Dozens of civilians have been joining Ukraine's army reserves in recent weeks amid fears about Russian invasion. (AAP Images/ AP Photo/Efrem Lukatsky) Source: AP
Mr Johnson "will reiterate the need for Russia to step back and engage diplomatically when he speaks to President Putin this week," a Downing Street spokeswoman said, stressing the prime minister's determination to "avoid bloodshed in Europe".
Meanwhile, Ukrainian President Volodymyr Zelenskiy says he cannot rule out a full-blown war with Russia but has accused the United States and media of fuelling panic that weighed on the economy while there are "no tanks in the streets".
He spoke after Russian President Vladimir Putin said the United States and NATO had not addressed Russia's main security demands in the stand-off over Ukraine but that he was ready to keep talking.
Speaking at a news conference, Mr Zelenskiy said: "I don't consider the situation now more tense than before. There is a feeling abroad that there is war here. That's not the case."
"Do we have tanks in our streets? No. But if you're not here you get the sense from the media that there's a war on. We don't need this panic," Mr Zelenskiy said.
He said that was the message he gave US President Joe Biden in their phone call on Thursday and that Russia was trying to intimidate Ukraine.
Ukraine was stabilising its hryvnia currency with FX reserves, as well as asking military, political and economic support from its allies, he said, adding the country needed up to $US5 billion ($A7.2 billion) to stabilise its economy.
"Constant and extremely emotional messages in the media about how a big war is going to start tomorrow, or the day after tomorrow or the day after that create economic risks," Mykhailo Podolyak, adviser to the president's chief of staff, said.
"This speculative stuff puts pressure on investors, creditors and on ordinary people. And that worsens other economic indicators."
According to one source familiar with their conversation, Mr Zelenskiy in his latest call with Biden on Thursday downplayed the risk of a Russian attack and focused on Ukraine's economy instead.
Ukrainian presidenti and popular comedian Volodymyr Zelenskiy. Source: AAP
On Friday, Mr Zelenskiy made clear he was frustrated with Mr Biden's war talk.
"I understand deeply what's going on in our state just as he (Mr Biden) deeply understands what's going on in the United States," Mr Zelenskiy said sharply.
He said it was important Mr Biden got his information about the situation from himself rather than intermediaries.
Mr Zelenskiy said the main risk for his country was destabilisation from within, including an economic crisis.
He said NATO was the only guarantor of hard security Ukraine saw in its stand-off, warning that the military alliance's eastern members might also be exposed to cyber-attacks and other intimidation tactics by Russia.
"This is a very serious challenge for NATO. Some European countries think: let's not risk, let's not take Ukraine in. But, if a full-blown war starts, it will also take place on the borders of some NATO countries."
He accused the United Kingdom of allowing money laundering by Russians but also by oligarchs siphoning money from countries including Ukraine and Kazakhstan.
Russia has played down accusations of a military build-up near Ukraine's border. Source: BBC
He criticised Germany prioritising business deals with Russia like the Nord Stream 2 gas pipeline over Ukraine's security and territorial integrity.
Mr Zelenskiy also said the decision by the US, UK, Australia, Germany and Canada to withdraw some of their diplomats and dependents from Kyiv was a "mistake".
"Those were redundant steps that didn't help," he said.
US Defense Secretary Lloyd Austin said on Friday that Mr Putin now has the military capability to act against Ukraine.
"While we don't believe that President Putin has made a final decision to use these forces against Ukraine, he clearly now has that capability," Mr Austin told reporters.
Russian President Vladimir Putin. Source: Pool Sputnik Kremlin
He said "there are multiple options available to including the seizure of cities and significant territories but also coercive acts and provocative political acts like the recognition of breakaway territories".
Mr Austin told reporters that the United States remains focused on countering Russian disinformation, including anything that could be used as a pretext for attacks against Ukraine.
Mr Austin said the United States was committed to helping Ukraine defend itself, including by providing additional anti-armour weaponry.
