KYIV, Ukraine (AP) — Russia has added as many as 7,000 troops near the Ukraine border in recent days, contrary to claims by President Vladimir Putin that troops would be pulled back from the region.

That's according to a senior Biden administration official who was not authorized to speak publicly about sensitive operations and spoke on condition of anonymity.

Russia has massed about 150,000 troops east, north and south of Ukraine, according to Western estimates.

Moscow denies it has any plans to invade, and this week announced a pullback of some forces and weapons.

While details are scarce, the Russian statements have lowered the political temperature following weeks of escalating tensions.

President Joe Biden addressed the potential conflict from the White House on Tuesday. He said the U.S. is prepared no matter which actions Russia takes. However, he was hopeful a diplomatic resolution could be reached.

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

According to CNN, Senators could vote, as soon as Thursday, on a bipartisan resolution that condemns Russia's aggression toward Ukraine.