President Joe Biden walks across the South Lawn of the White House in Washington, D.C., on Friday. He spoke Sunday with Ukrainian President Volodymyr Zelensky regarding a possible invasion of Ukraine by Russia. Photo by Shawn Thew/UPI | License Photo
Feb. 13 (UPI) -- President Joe Biden on Sunday told his Ukrainian counterpart, Volodymyr Zelensky, the United States would respond "swiftly and decisively" to a Russian invasion of his country, the White House said.
"President Biden made clear that the United States would respond swiftly and decisively, together with its Allies and partners, to any further Russian aggression against Ukraine," the administration said in a readout of the call with Zelensky.
The two leaders, they said, "agreed on the importance of continuing to pursue diplomacy and deterrence in response to Russia's military build-up on Ukraine's borders."
The conversation came after Zelensky in recent days has played down the threat of an invasion, saying warnings from the United States that a Russian move is imminent are not helpful for maintaining order.
"All this information helps only to create panic. It doesn't help us," he said.
Ukraine has also said there were no plans to close civilian air space, as Foreign Minister Dmytro Kuleba asserted that the "situation remains under control" in a video statement released Sunday.
"We are prepared for any scenario of development of events," he said. "We have not been sitting with our arms folded for the last months, we have prepared for all scenarios -- absolutely all -- and as of now we are ready for them."
U.S. national security adviser Jake Sullivan, however, issued another such warning earlier Sunday, declaring that Russia's military buildup surrounding Ukraine has reached the point that an invasion could take place "any day now."
Sullivan told CNN's State of the Union that the United States has observed an "acceleration" of Russia's build-up of military forces in the past 10 days that indicates the military could launch action "very, very rapidly."
"We cannot perfectly predict the day, but we have now been saying for some time that we are in the window, and an invasion could begin, a major military action could begin by Russia in Ukraine any day now -- that includes this coming week, before the Olympics," he said.
Sullivan said the United States still believes Russia could choose a "diplomatic path" but the United States on Friday warned all Americans in Ukraine to leave the country within 48 hours in preparation for a potential invasion.
"The way they have built up their forces, the way they have maneuvered things in place makes it a distinct possibility that there will be major military action very soon," he said. "And we are prepared to continue to work on diplomacy, but we are also prepared to respond in a united and decisive way with our allies and partners should Russia proceed."
An assessment based on new intelligence and evidence on the ground released Friday showed that Russia is fully prepared to launch an attack with 130,000 troops and major weaponry surrounding Ukraine on three sides, The Washington Post reported.
Russia has also been conducting military exercises in southern Russia, the Black Sea and Belarus, which borders Ukraine to the north.
Sullivan said an attack would likely begin with "a significant barrage of missiles and bomb attacks" that could kill civilians, which is why the United States has urged Americans to leave the country while commercial transport options are still available.
"Those are never as precise as the army -- any army -- would like them to be. We don't even know how precise the Russian army would like them to be," he said of the missile and bomb attacks. "Innocent civilians could be killed regardless of their nationality. It would then be followed by an onslaught of a ground force moving across the Ukrainian frontier. Again, where innocent civilians could get caught in the crossfire or trapped in places they could not move from."
Israel has also sent messages urging the approximately 15,000 Israeli citizens in the country to leave immediately.
In addition, Sullivan reiterated the possibility that Russia could use a false flag operation as a pretext to launch the invasion.
"We have information that we have gathered through intelligence that indicates that there is active planning for this, and it's not just the United States saying it," Sullivan said. "We have our NATO allies stepping out and saying it as well, because they've been able to review that intelligence, assess its credibility and reach the same conclusion we have reached. So I do think the world should be prepared for Russia staging a pretext and then launching a potential military action."
Sullivan said the United States has been pursuing transparency surrounding the situation to ensure that Russia is not provided the opportunity to "spring something on Ukraine or the world."
"We are going to make sure that we are laying out for the world what we see as transparently and plainly as we possibly can and share that information as widely as we can," he said. "That's what we've done. That's what we'll continue to do."
U.S. President Joe Biden is set to speak with Zelensky by phone on Sunday, Zelensky's spokesman Sergii Nykyforov confirmed via Facebook.
The call comes a day after Biden warned Russian President Vladimir Putin on a phone call of "swift and severe costs" if Russia moves forward with an invasion against Ukraine.
German Chancellor Olaf Scholz is also set to meet with Zelensky in Kiev on Monday and Putin in Moscow on Tuesday.
Last week, French President Emmanuel Macron said he'd received assurance from Putin that he would not escalate the tensions..