BRUSSELS (Reuters) - NATO's secretary general said on Tuesday he had seen no evidence that Russia is withdrawing its forces from the border with Ukraine.

"Unfortunately, I cannot confirm that Russia is withdrawing its troops," Anders Fogh Rasmussen told reporters ahead of a meeting of NATO foreign ministers in Brussels.

"This is not what we are seeing."

Rasmussen said Russia had undermined the principles on which a NATO-Russia partnership had been built, and that as a result there could be no more "business as usual".

(Reporting by Adrian Croft, editing by Luke Baker)