In Ukraine, where people raised flags and played the national anthem to show unity against fears of an invasion, the government said a cyber attack that hit the defence ministry was the worst of its kind the country had seen. It pointed a finger at Russia, which denied involvement.
White House press secretary Jen Psaki said US officials were as yet unable to say who was responsible for the cyber attack. She also said the door remained open for diplomacy with Russia but reiterated concerns that a Russian attack could be preceded by a 'false flag' operation and misinformation.
Russia's defence ministry said its forces were pulling back after exercises in southern and western military districts near Ukraine.
It published video that it said showed tanks, infantry fighting vehicles, and self-propelled artillery units leaving the Crimean peninsula, which Moscow seized from Ukraine in 2014.
But US Secretary of State Antony Blinken said key Russian units were moving towards the border, not away.
"There's what Russia says. And then there's what Russia does. And we haven't seen any pullback of its forces," Blinken said in an interview on MSNBC. "We continue to see critical units moving toward the border, not away from the border."
A senior Western intelligence official said the risk of Russian aggression against Ukraine would remain high for the rest of February and Russia could still attack Ukraine "with essentially no, or little-to-no, warning".
NATO Secretary-General Jens Stoltenberg said moving troops and tanks back and forth did not amount to proof of a pullout.
"What we see is that they have increased the number of troops and more troops are on their way. So, so far, no de-escalation," he said before an alliance meeting in Brussels.
Stoltenberg later said NATO could prove Russia's failure to pull back its troops with satellite imagery.
Ukraine's Defence Minister Oleksii Reznikov told Reuters in an interview his country's latest intelligence report similarly showed no sign of a Russian pullback. He said the combined strength of Russian military and pro-Russian separatist forces near Ukraine's borders stood at about 140,000.
The Kremlin said NATO's assessment was wrong and it never planned to attack Ukraine but wants to lay down "red lines" to prevent its neighbour from joining NATO, which it sees as a threat to its own security.
It accused Washington of hysterical war propaganda after repeated warnings of a possible attack and reports in some Western media that it would happen on Wednesday.
Ukrainian President Volodymyr Zelenskiy designated Wednesday a patriotic holiday in response to the reports Russia might invade. "No one can love our home as we can. And only we, together, can protect our home," he said.
Zelenskiy, who is criss-crossing the country to help bolster Ukrainians' morale, observed drills by his armed forces that included Javelin anti-tank missiles in western Ukraine.
