Moscow (AFP) - A comment attributed to President Vladimir Putin warning that Russia could capture Kiev in two weeks was taken out of context, his top foreign policy aide said Tuesday.

"Whether these words were said or not I believe the quote that you cite has been taken out of context and had a completely different meaning," aide Yuri Ushakov told journalists.

Italy's La Repubblica newspaper reported a summary of a debate at last weekend's EU summit citing European Commission chief Jose Manuel Barroso as saying he had spoken by telephone with Putin.

The paper said the Kremlin strongman declined to answer questions about Russian troops operating in Ukraine and threatened: "If I wanted I could take Kiev in two weeks."

Ushakov criticised Barroso, saying discussion of the content of their call "goes beyond the framework of diplomatic practice" and "is simply not worthy of a serious political figure".

In an unusually short briefing, Ushakov testily refused to answer questions about whether Russian troops are fighting in Ukraine.

"Appropriate explanations have already been given," he said.