White House spokesman Jay Carney told reporters on Monday that US officials had seen no indication that Russian troops were redeploying away from the border area.

"We'll want to see clear, firm evidence of this move before we make any judgment," Carney said.

"We would know and would be able to confirm for you if the Russian military had moved back," he added in an apparent reference to US surveillance capabilities.

Carney spoke just hours after NATO Secretary General Anders Fogh Rasmussen said the Western military alliance also had not seen any evidence of Russian troops moving away from the border area.

Both were reacting to a statement from the office of Russian President Vladimir Putin earlier on Monday, indicating that he had ordered the troops to withdraw from the border region and return to barracks after completing spring exercises.

A similar announcement earlier this month was also quickly dismissed by both US and NATO officials.

Russian warning for NATO

Meanwhile, the chief of the general staff of Russia's armed forces has used a telephone conversation to warn the chairman of NATO's Military Committee, Knud Bartels, that the alliance's increased military activity in the region was not helping to calm tensions in eastern Ukraine.

"Army General Valery Gerasimov expressed concern over the substantial increase of NATO military activity near the Russian border, which does not contribute to security in Europe," the statement issued by the defense ministry in Moscow said.

Concerns about election conditions

Also on Monday, a senior United Nations official expressed serious concerns about the conditions under which Ukrainians are to go to the polls on Sunday.

"We do have information on a number of presidents, of vice presidents of electoral commissions being abducted, being maltreated (in the east of the country), with implications for a number of other members of the commissions," Ivan Simonovic, the UN's Assistant Secretary-General for Human Rights told the Reuters news agency while on a visit to Kyiv.

Interior Minister Arsen Avakov had earlier conceded that the security situation in Donetsk and neighboring Luhansk meant that "there is no way to hold elections in a normal way."

Political talks on the weekend aimed at easing tensions failed to produce any tangible results.

Fighting broke out in eastern Ukraine last month after the government launched an offensive against pro-Russian separatists who seized control over a dozen towns and declared independence from Kyiv for Donetsk and Luhansk.

pfd/dr (Reuters, AFP)