U.S. President Joe Biden's administration says it wants to be prepared in case Russia invades Ukraine and the onus is on Moscow to change its behavior toward its neighbor, as warnings over a buildup of Russian troops near the border intensified on December 3.
The White House rebutted Russian demands this week over the West's relations with Ukraine by saying that "NATO decides who joins NATO, not Russia," and added that U.S. security assistance to Ukraine remains under consideration.
Administration spokeswoman Jen Psaki also said that the United States was ready to impose sanctions or take other punitive measures against Russia if it escalates its actions with respect to Ukraine.
The White House declined to say whether military planning is among the moves being considered as part of a "comprehensive" set of measures for Ukraine.
It also said it couldn't tell what Russian President Vladimir Putin's plans were with respect to Ukraine but that Moscow had taken steps that could allow for an invasion.
"That is why we want to be prepared and in an area we have expressed serious concern about," Psaki said.
Biden said hours earlier that he was readying initiatives to "make it very, very difficult" for Russia to escalate militarily against Ukraine, as Kyiv expressed fears of an attack next month amid a troop buildup in western Russia.
The warning came after a Russian official suggested Biden and Putin would speak by video "within days" but possibly after the Russian leader's scheduled trip next week to India.
Psaki said the White House was preparing for a possible call with Putin to discuss the Ukrainian situation.
"What I am doing is putting together what I believe to be the most comprehensive and meaningful set of initiatives to make it very, very difficult for Mr. Putin to go ahead and do what people are worried he's going to do," Biden said.
Biden told reporters that his administration was in "constant contact" with Ukraine and European allies about the situation, following weeks of reports that more than 90,000 Russian troops, tanks, and heavy weaponry were amassing near the border with Ukraine.
Russia invaded and forcibly seized Ukraine's Crimean Peninsula in 2014, while Russia-backed separatists also launched a conflict in eastern Ukraine against the Kyiv central government. Peace efforts have lowered the intensity of fighting but commitments on both sides remain unmet.
NATO and Western leaders have repeatedly warned of consequences if Russia escalates the situation militarily.
Earlier on December 3, Ukrainian Defense Minister Oleksiy Reznikov told lawmakers that Ukrainian intelligence had "emphasize[d] that the likelihood of large-scale escalation by Russia exists."
In an address to Ukrainian parliamentary deputies, Reznikov added that "the most likely time we must be ready to stand against such an escalation will be the end of January." He said the best way to reduce the threat was to "work together with our [Western] partners" and "make the price of possible escalation unacceptable for the aggressor."
Putin aide Yury Ushakov said that "a concrete date and time" for a videoconference between Biden and Putin was set but that "it is better to wait until all the parameters are fully agreed on with the American side, and then, we will be able to officially announce it."
SEE ALSO: Kremlin Says Preliminary Date Set For Putin-Biden Video CallHe added that Putin would repeat a demand by Moscow for a legally binding commitment to “exclude any further NATO expansion eastward and the deployment of weapons systems that would threaten us on the territories of neighboring countries, including Ukraine.”
Moscow has consistently denied participating in the Ukrainian conflict despite overwhelming evidence of troops, equipment, and other Russian support for the separatists in a war that has killed more than 13,200 people.
Putin reportedly spoke to Turkish President Recep Tayyip Erdogan on December 3 and complained of Ukraine's use of Turkish-made drones in the ongoing conflict.
He called the alleged use of Bayraktar unmanned aerial vehicles "provocative," the Kremlin said.
Erdogan was quoted as saying on November 29 that he was willing to act as a mediator between Ukraine and Russia, despite strained relations over Ankara's sale of armed drones to Kyiv earlier this year.
On December 1, Russia's Defense Ministry said that more than 10,000 Russian troops had started military exercises near the Ukrainian border.
U.S. Secretary of State Antony Blinken said after meeting Russian Foreign Minister Sergei Lavrov on December 2 in Stockholm that "the United States and our allies and partners are deeply concerned by evidence that Russia has made plans for significant aggressive moves against Ukraine, including efforts to destabilize Ukraine from within and large-scale military operations."
SEE ALSO: Blinken Warns Russia Of 'Significant Costs' In Case Of Aggression Against UkraineLavrov told Blinken that Moscow needed "long-term security guarantees," which would halt NATO's eastward expansion.
Army General Mark Milley, chairman of the U.S. Joint Chiefs of Staff, cited "significant national security interests of the United States and of NATO member states" if Russia attacked Ukraine.