The North Atlantic Treaty Organisation (NATO) said on Monday it was putting forces on standby and reinforcing Eastern Europe with more ships and fighter jets, in what Russia denounced as an escalation of tensions over Ukraine.
The move added to a flurry of signals that the West is bracing for an aggressive Russian move against Ukraine.
The Kremlin, in response, accused the West of “hysteria”.
“NATO will continue to take all necessary measures to protect and defend all allies, including by reinforcing the eastern part of the alliance,” NATO Secretary-General Jens Stoltenberg said in a statement.
Britain said it was withdrawing some staff and dependants from its embassy in Ukraine in response to “a growing threat from Russia”, a day after the United States said it was ordering diplomats’ family members to leave.
“Military action by Russia could come at any time,” the U.S. Embassy said in a statement.
Officials “will not be in a position to evacuate American citizens in such a contingency, so U.S. citizens currently present in Ukraine should plan accordingly,” it added.
U.S. diplomats at the embassy in Kyiv were being allowed to leave voluntarily.
Shares across the world fell as the risk of conflict quashed demand for riskier assets, and tension over Ukraine was among the factors that pushed up oil prices.
Russia denies planning to invade Ukraine but has used its build-up of an estimated 100,000 troops near the border to force the West to negotiate over a range of demands to redraw the security map of Europe.
It wants NATO to scrap a promise to let Ukraine join one day and to pull back troops and weapons from former Communist countries in eastern Europe that joined it after the Cold War.
Washington says those demands are non-starters but it is ready to discuss other ideas on arms control, missile deployments, and confidence-building measures.
The United States and the European Union, wary of Russia’s intentions since it seized Crimea and backed separatists fighting government forces in eastern Ukraine in 2014, have warned Russia not to invade.
Denmark said the EU was ready to impose “never-seen-before” economic sanctions and EU foreign ministers meeting in Brussels said they would send a unified warning to Moscow.
The rouble hit a 14-month low against the dollar, while Russian stocks tumbled.
The dollar-denominated RTS share index was down 8.9 per cent, and the rouble-based MOEX down 6.8 per cent.
Russia is awaiting a written response to its demands this week after talks last Friday – the fourth round this month – produced no breakthrough.
Having engineered the crisis by surrounding Ukraine with Russian forces from the north, east, and south, Moscow is now citing the Western response as evidence that it is under threat from NATO and Ukraine.
“As for specific actions, we see statements by the North Atlantic Alliance about reinforcement, pulling forces and resources to the eastern flank.
All this leads to the fact that tensions are growing,” Kremlin spokesman Dmitry Peskov said.
“This is not happening because of what we, Russia, are doing. This is all happening because of what NATO and the U.S. are doing and due to the information they are spreading.”
He said the West was showing “hysteria” and putting out information “laced with lies”.
The NATO statement said Denmark, Spain, France, and the Netherlands were all planning or considering sending troops, planes, or ships to eastern Europe.
Ukraine shares borders with four NATO countries: Poland, Slovakia, Hungary, and Romania.
President Joe Biden has begun considering options for boosting U.S. military assets in the region, senior administration officials said, after he met top national security aides at his Camp David retreat on Saturday.
The New York Times said Biden was mulling plans to send 1,000 to 5,000 troops to eastern European countries, with the possibility of increasing the number should tensions flare further.
A senior administration official declined to confirm the numbers on Sunday but said “we are developing plans and we are consulting with allies to determine options moving forward.”
Ukraine’s Foreign Ministry said in a statement that it considered the move to send home U.S. diplomats’ families as “premature and a manifestation of excessive caution.”
“In fact, there have been no cardinal changes in the security situation recently: the threat of new waves of Russian aggression has remained constant since 2014 and the buildup of Russian troops near the state border began in April last year,” it said.
Britain said at the weekend it had information the Russian government was considering a former Ukrainian lawmaker as a potential candidate to head a pro-Russian puppet leadership in Kyiv.
The Russian Foreign Ministry dismissed the British allegation as “disinformation,” accusing NATO of escalating tensions over Ukraine.
