Senior White House counselor John Podesta speaks during the daily briefing at the White House on May 5, 2014
A White House spokesman said Wednesday that US officials have seen "no evidence" that Russian troops have pulled back from the tense border with Ukraine.
Russian President Vladimir Putin had earlier said that the estimated 40,000 Russian troops deployed on the frontier had withdrawn to their usual training grounds.
But, speaking to reporters on Air Force One, White House deputy spokesman Josh Earnest said that "to date" there has been "no evidence that such a withdrawal has taken place."
He added that Washington would "certainly welcome" such a development.
Earnest made his remarks after the Russian leader met with Swiss President Didier Burkhalter, current chief of the Organization for Security and Cooperation in Europe.
Putin said of the troops he had ordered to Ukraine's border two months ago: "We have pulled them back. Today they are not at the Ukrainian border but in places of regular exercises, at training grounds."
Putin said he also told pro-Russian separatists "to postpone the referendums planned for May 11 in order to create the conditions necessary for dialogue."