U.S. and Israeli officials are dismissing an eyebrow-raising claim from a prominent Palestinian activist and official, Mustafa Barghouti, in today’s International Herald Tribune. “The Israeli foreign minister, Avigdor Lieberman, stands up and walks out on the U.S. envoy, George Mitchell, every time the American envoy mentions East Jerusalem,” Barghouti wrote in an op-ed deploring “U.S. and European inaction” in the face of Israeli intransigence. Israeli Ambassador Michael Oren, through a spokesman, dismissed the claim as “nonsense.” “I have never heard such a thing,” added the spokesman, Jonathan Peled. A senior U.S. official who has attended meetings with Lieberman and Mitchell called the claim “absurd” and “patently untrue.” “Never happened,” said the official.