Speaking to his human rights council, Mr Putin recalled watching a congressional debate where Mr Kerry was asked about al-Qaeda. Mr Putin said he had denied that it was operating in Syria, even though he was aware of the al-Qaeda-linked Jabhat al-Nusra group.
Mr Putin said: "This was very unpleasant and surprising for me. We talk to them (the Americans) and we assume they are decent people, but he is lying and he knows that he is lying. This is sad."
Maybe something got lost in translation - as best we can tell, Kerry didn't say Al Qaeda was not operating in Syria at all; he said their influence was on the wane. But Reuters disputes even that:
(Reuters) - Secretary of State John Kerry's public assertions that moderate Syrian opposition groups are growing in influence appear to be at odds with estimates by U.S. and European intelligence sources and nongovernmental experts, who say Islamic extremists remain by far the fiercest and best-organized rebel elements.
Kerry took one pass at this in the House hearing on Wednesday:
In a second hearing on Wednesday, Kerry was challenged by Representative Michael McCaul, Texas Republican.
"Who are the rebel forces? Who are they? I ask that in my briefings all the time," McCaul said. "And every time I get briefed on this it gets worse and worse, because the majority now of these rebel forces - and I say majority now - are radical Islamists pouring in from all over the world."
Kerry replied: "I just don't agree that a majority are al Qaeda and the bad guys. That's not true. There are about 70,000 to 100,000 oppositionists ... Maybe 15 percent to 25 percent might be in one group or another who are what we would deem to be bad guys.
"There is a real moderate opposition that exists. General Idriss is running the military arm of that," Kerry continued, referring to General Salim Idriss, head of the rebel Free Syrian Army. Increasingly, he said, Saudi Arabia and other Gulf states are funneling assistance through Idriss.
Kerry said this in a Senate hearing on Tuesday:
It was unclear exactly what Mr Putin was referencing, but Mr Kerry was asked on Tuesday while testifying before the Senate Foreign Relations Committee if the Syrian opposition had become more infiltrated by al-Qaeda.
Mr Kerry responded that that was "basically incorrect" and that the opposition has "increasingly become more defined by its moderation."