The United States has made clear to President Vladimir Putin that any Russian movement into Ukraine would be considered an invasion, President Joe Biden said on January 20.
"I have been absolutely clear with President Putin. He has no misunderstanding. If any, any assembled Russian units move across the Ukrainian border, that is an invasion," Biden told reporters at the White House.
Alarms have been sounding throughout Western capitals about the danger of a new major conflict after Russia massed an estimated 127,000 troops along Ukraine’s borders and deployed a sizable force in Belarus for what Moscow and Minsk say will be snap military exercises.
Any such invasion would be met with a "severe and coordinated" economic response that has been discussed in detail with U.S. allies, Biden said, "as well as laid out very clearly for President Putin."
"But there is no doubt, let there be no doubt at all, that if Putin makes this choice, Russia will pay a heavy price," he added.
Biden's warning came shortly after Secretary of State Antony Blinken and Washington’s major allies in Europe met in Berlin to discuss the Ukraine crisis as concerns continue to rise that the buildup of Russian troops on its border with Ukraine is a prelude to an attack at "very short notice."
Blinken met with his counterparts from Germany, France, and the United Kingdom and said that if any Russian forces move across the Ukrainian border there will be a “swift, severe response from the United States and our allies and partners.”
Speaking at a joint news conference with Blinken, German Foreign Minister Annalena Baerbock said the ministers “urge Russia to take steps towards a de-escalation” of the situation.
"Any further aggressive stance, any further aggression, would have grave consequences," Baerbock said.
The meeting of allies comes a day before Blinken heads to Geneva for talks with Russian Foreign Minister Sergei Lavrov.
Blinken said Russia could use a wide array of actions to destabilize the situation, including hybrid and paramilitary attacks on Ukraine.
Blinken visited Kyiv on January 19 to reassure Ukraine that it had the support of Washington, saying that if Russia carries through with any aggressive moves against Ukraine, the United States is prepared to provide additional materials to Kyiv to help it defend itself.
Meanwhile, NATO Secretary-General Jens Stoltenberg underlined the unity of the alliance in an interview with CNN.
"All NATO allies have made it clear several times that we will react if Russia once again conducts aggressive actions against Ukraine," Stoltenberg said on January 20.
On January 19, Biden had said Putin likely hasn't decided and that Russia would face severe economic consequences should a military offensive occur.
Stoltenberg also said that Biden, who referred to a possible "minor incursion" by Russia the previous day, was not a green light for a potential Russian invasion of Ukraine.
"Not at all," Stoltenberg told CNN. "Russia will be held accountable if it invades -- and it depends on what it does,"
Mykhaylo Podolyak, an adviser to President Volodymyr Zelenskiy's office, said Kyiv welcomed that Biden had signaled a coordinated Western response in case Russia made a move on Ukraine.
"What was important for Ukrainian society to hear? The fact that Western states have a common understanding that any negative scenario in relation to Ukraine or in general in Europe will receive a coordinated, sufficient and sensitive response," Podolyak wrote in a message to Reuters.
"At the same time, it is important to understand that diplomatic efforts at various levels continue, and de-escalation steps are now the main goal of these efforts."
The Kremlin, which denies planning an attack, said on January 20 that the U.S. warning of possible disastrous consequences for Russia could destabilize the situation further.
British Prime Minister Boris Johnson told reporters in London on January 20 that any move by Russia to invade Ukraine “would be a disaster for the world.”
European Commission President Ursula von der Leyen reiterated on January 20 that the EU will respond with "massive" economic and financial sanctions "if the situation deteriorates, if there are any further attacks on the territorial integrity of Ukraine."
The transatlantic community "stands firm in this," von der Leyen said in an online address to the World Economic Forum in Davos, Switzerland.
"We do not accept Russia's attempt to divide Europe into spheres of influence," she said. "If attacks happen, we are prepared."
Russian Foreign Ministry spokeswoman Maria Zakharova on January 20 alleged that Ukrainian and Western claims of an imminent Russian attack on Ukraine were "cover for staging large-scale provocations of their own, including those of a military character."
Zakharova cited the delivery of weapons to Ukraine by British military transport planes in recent days.
The United States has reportedly approved requests by Baltic countries to ship U.S.-made weapons to Ukraine.
A State Department official in Berlin said the United States was "expediting authorized transfers of U.S.-origin equipment from other allies," according to AFP and Reuters.
"European allies have what they need to move forward on additional security assistance [to] Ukraine in the coming days and weeks," the official said.
A source familiar with the authorizations was quoted as saying the approval was for urgent requests by NATO members Estonia, Latvia, and Lithuania to assist Ukraine. The exact amounts and types of weapons were not specified.
Last week, Russian diplomats met with top officials from the United States, NATO, and European countries to discuss the sweeping demands Moscow has made, which amount to a major restructuring of Europe's security architecture.
The talks yielded no breakthroughs, and that, plus belligerent rhetoric from Moscow, has alarmed Western officials.
In a related development, Turkish President Recep Tayyip Erdogan said on January 20 that he will travel to Ukraine early next month and voiced hope of bringing together the Russian and Ukrainian leaders as soon as possible.
"In the early days of next month, I have a visit to Ukraine," Erdogan told a news conference in Ankara. "Our hope is for peace to reign in the region."
NATO member Turkey has good ties with both Ukraine and Russia but opposed the latter's annexation of Crimea in 2014.
Kyiv has welcomed Turkey's involvement in negotiations with Russia. Zelenskiy said in November that he had asked Erdogan to hand Putin a list of prisoners for a potential prisoner swap, though the swap never materialized.