State Department spokesman Ned Price said in a press conference that the United States was concerned about any attempt by Moscow to intimidate Ukraine either from Russian territory or by moves inside Ukraine.
However, he declined to answer whether the United States believe Russia is preparing to invade Ukraine.
“We urge Russia to avoid actions of escalation” the spokesman said.
The comments came after a phone call on Friday in which Biden assured his Ukrainian counterpart, Volodymyr Zelensky, of “irrevocable support” for Ukraine’s confrontation with Russian-backed separatists that have occupied parts of eastern Ukraine’s region Donbass.
Russia on Monday denied that Russian army units on the border pose a threat to Ukraine and rejected fears of a massive military build-up.
White House Press Secretary Jen Psaki told reporters that “the recent escalation of Russian aggression and the escalation in eastern Ukraine is something we are watching closely.”