Russian President Vladimir Putin has repeated his insistence that Ukraine should not join NATO, while U.S. President Joe Biden says that Washington has no intention of sending U.S. troops to defend Ukraine against any new Russian invasion.
The two leaders spoke in separate appearances on December 8, one day after they met for a two-hour videoconference amid fears of a new war over Ukraine.
The talks - their third direct meeting since Biden took office in January- came as tens of thousands of Russian troops have deployed to regions near the Ukraine borders. Ukrainian officials put the number at just below 100,000, while U.S. intelligence has warned the figure could reach 150,000 in the near future.
It's one of the largest movements of Russian forces toward Ukraine in years, outside of regularly scheduled training exercises.
That, plus the absence of more routine notification procedures shared even between adversaries, has set off alarm bells, not only in Ukraine, but in many NATO countries, particularly those in Eastern Europe.
In Washington, Biden said he had warned Putin that if Russia launched a new invasion against Ukraine, the United States would retaliate with sanctions 'like none he's ever seen."
'I made it very clear, if in fact he invades Ukraine, there will be severe consequences, severe consequences -- economic consequences like none he's ever seen or ever have been seen,' he told reporters.
But Biden also said no U.S. troops would be sent to Ukraine to help defend against a Russian invasion.
'The idea the United States is going to unilaterally use force to confront Russia invading Ukraine is not in the cards right now,' the U.S. president said, according to a White House transcript.
SEE ALSO: Biden Says No U.S. Troops Will Be Deployed To Ukraine In Event Of Russian Invasion
Neither Russian nor U.S. officials have described the December 7 conference call as yielding any breakthroughs.
In Moscow, Putin characterized the talks as 'very open, substantive, and constructive.'
'We have an opportunity to continue the dialogue. This is most important,' the Russian president said.
Earlier, Kremlin spokesman Dmitry Peskov said that the two sides planned more meetings of envoys in the coming weeks.
SEE ALSO: He Said, He Said: Russian, U.S. Statements On Biden-Putin Call Differ Starkly
In Ukraine, President Volodymyr Zelenskiy, who was scheduled to speak with the U.S. president on December 9, called the Putin-Biden talks positive, saying that 'the United States has always supported Ukraine, our sovereignty and independence.'
'But the most important thing is that now we see a real and personal reaction from President Biden and his personal role in resolving the conflict,' Zelenskiy said.
Though Ukraine is not a member of NATO, and is unlikely to be for some years, Russia views the prospect of Kyiv joining the Western alliance as a threat following NATO's expansion into nations from the former Soviet bloc as well as ex-communist Central and Eastern European states in the late 1990s and early 2000s.
Russia asserts Kyiv is failing to meet its commitments under the 2014 and 2015 Minsk agreements aimed at putting an end to the conflict.
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It was unclear exactly what punishment the Biden administration is threatening to wield if Russia were to launch an attack on Ukraine.
Some analysts have pointed to the possibility Russia could be cut off from the international system of financial payments known as SWIFT, which would hit Russian banks hard.
Another possible punitive measure would be a renewed effort to block Nord Stream 2, the Baltic Sea pipeline that will significantly increase Russian gas supplies to Europe via Germany once it is approved by regulators.
Earlier this year, the Biden administration reached a deal with Germany that averted sanctions on the pipeline's operator, removing a major irritant in relations between the two allies.
But in recent days German officials have warned a Russian invasion of Ukraine would put an end to the pipeline.
France, meanwhile, warned Moscow on December 8 it would face 'strategic and massive consequences' if Russia attacked Ukraine.
The French Foreign Ministry also said that in phone calls between five major Western allies -- France, Britain, Italy, Germany, and the United States -- leaders agreed that 'the sovereignty of Ukraine be respected.'
Ukraine has been fighting a war against Kremlin-backed separatists in eastern Ukraine since early 2014 that has killed more than 13,200 people.
After Biden and Putin met in Geneva in June, many experts hoped that the Ukraine conflict would inch toward resolution, as Washington and Moscow looked for ways to arrest the downward spiral in relations.
The two leaders also spoke by telephone in July, when Biden called on Putin to do more to crack down on ransomware and hacking attacks against the United States. Many of the leading ransomware groups either operate in, or originate from, Russia.
Copyright (c) 2018. RFE/RL, Inc. Republished with the permission of Radio Free Europe/Radio Liberty, Washington DC 20036