A senior Biden administration official said Wednesday that Russia has added as many as 7,000 troops at the border with Ukraine, characterizing claims by Moscow that it was withdrawing forces as “false.”

“We have now confirmed that in the last several days, Russia has increased its troop presence along the Ukrainian border by as many as 7,000 troops, with some arriving as recently as today," the official told reporters on a call Wednesday evening.

“Every indication we have now is they mean only to publicly offer to talk and make claims about de-escalation while privately mobilizing for war,” the official said, adding that the U.S. is receiving indications that Russia could launch a false pretext to justify an invasion of Ukraine “at any moment.” 

The official said that a false pretext could take multiple forms, including a provocation in the Donbas region of Ukraine, a claim about NATO military activity, or an incursion into Russia’s own territory. 

The comments directly challenged Russian statements about pulling back some forces and being willing to engage in diplomacy over the past 24 hours. 

Biden administration officials have warned since Friday that Russia has amassed enough troops on Ukraine’s border to launch a military attack at any moment. 

U.S. and European officials have said they have seen no signs of Russia de-escalating the situation, despite a statement by Russia on Tuesday that it was pulling back troops. Before Wednesday, the U.S. estimated that Russia had amassed 130,000 troops on the Ukrainian border.

“We continue to see forces, especially forces that would be in the vanguard of any renewed aggression against Ukraine, continuing to be at the border, to mass at the border,” Secretary of State Antony Blinken said during an appearance on ABC’s “Good Morning America” on Wednesday.

Lt. Gen. Sir Jim Hockenhull, the U.K. defense intelligence chief, said in a statement earlier Wednesday that Russia “continues to build up military capabilities near Ukraine.” 

“This includes sightings of additional armoured vehicles, helicopters and a field hospital moving towards Ukraine’s borders. Russia has the military mass in place to conduct an invasion of Ukraine,” he said.  

And NATO Secretary General Jens Stoltenberg said that Russia appeared to be continuing their military buildup in comments to reporters. 

Biden administration officials did not elaborate on the intelligence supporting the estimate that Russia has added as many as 7,000 troops to the border with Ukraine. 

A second senior administration official declined to offer underlying information but said it could be taken “as fairly authoritative.” 

In a speech Tuesday afternoon, President Biden welcomed the Russian statement that Moscow would pull back forces but said it had not been verified. He warned Russian President Vladimir Putin against invading Ukraine but vowed to give diplomacy "every chance to succeed" in diffusing the crisis.  

“As long as there is hope of a diplomatic resolution that prevents the use of force and avoids the incredible human suffering that would follow, we will pursue it,” Biden said.  

Updated: 7:42 p.m.