Just a few days ahead of a trip to meet with his Russian counterpart Sergei Lavrov, US Secretary of State John Kerry accused Moscow of lying "to my face" on Tuesday about its role in the Ukraine conflict.

Though the diplomat declined to say publicly whether he was in favor of supplying weapons to Ukrainian troops, when asked by US lawmakers whether Russia was lying when it denied that there were Russian troops or weapons in Ukraine, Kerry answered with a definitive "yes."

"Russia has engaged in a rather remarkable period of the most overt and extensive propaganda exercise that I've seen since the height of the Cold War," Kerry told a Senate subcommittee meeting about the State Department budget.

He continued: "And they have been persisting in their misrepresentations - lies - whatever you want to call them - about their activities to my face, to the face of others, on many different occasions."

Kerry said his Saturday meeting with Russian Foreign Minister Lavrov will be to discuss "Syria and other things" before leaving for Iran to continue negotiations on their nuclear program.

Before wrapping up, Kerry appeared to take a swipe at Israeli Prime Minister Benjamin Netanyahu, who is scheduled to speak before the US Congress on the subject of Iran in March at the invitation of Congressional Republicans in defiance of protocol.

"Anybody running around right now jumping in to say, 'Well we don't like the deal,' or this or that, doesn't know what the deal is. There is no deal yet," Kerry told the senators, "and I caution people to wait and see what these negotiations produce."

es/bw (AFP, Reuters)