Ukrainian border guards say there has been a decrease in Russian military activity near their border, but NATO and the USA say they have seen no signs that Russian forces have pulled back.
On Monday the Kremlin announced President Vladimir Putin had ordered Russian forces near Ukraine back to their bases.
The White House said it was the third time Moscow had said it had pulled back, and like the last times there was no evidence of a significant withdrawal.
“At this point we see no indication of any movement which has been the case as you know several times before,” said White House spokesman Jay Carney.
NATO also denied it had any proof the Russians were seeking to make good their promise of helping to calm a dangerously tense situation.
“I strongly regret that, because a withdrawal of Russian troops would be a first important contribution to de-escalating the crisis,” said NATO Secretary General Anders Fogh Rasmussen.
However Moscow did welcome what it called “initial contacts” between the interim government in Kyiv and “supporters of federalisation” in eastern Ukraine, in a first round-the-table debate. Germany’s Angela Merkel also welcomed the start of dialogue.