The White House expressed skepticism Wednesday over Russian President Vladimir Putin's claim that he had pulled back troops from the Ukrainian border.

“I will say that to date there has been no evidence that such a withdrawal has taken place,” White House spokesman Josh Earnest said of Putin's declaration earlier Wednesday.

Putin said Russian troops were removed Wednesday from the Ukrainian border but provided no further information about their exact whereabouts.

The Russian leader, in a surprising shift, also urged Russian separatists to postpone a referendum scheduled for Sunday in southeast Ukraine.

The White House welcomed Putin's remarks but said he should have called for the cancellation of the referendum altogether.

“In terms of President Putin’s comments about the May 11 referendum, we have said repeatedly that this referendum is illegitimate, illegal,” Earnest said.

Last week, President Obama, along with German Chancellor Angela Merkel, threatened additional sanctions against the Russian economy if the Russians interfered with Ukrainian elections planned for May 25.

The White House also called Wednesday on the Kremlin to do more to ensure those elections took place.