George Mitchell's visit to Jerusalem and the West Bank will be his first since Israeli Prime Minister Benjamin Netanyahu returned a month ago from low-profile talks with US President Barack Obama that underscored a rift between the two leaders.
Netanyahu still has not responded publicly to what political sources have said was a list of 11 "confidence-building" steps Obama wants him to take to coax the Palestinians back into negotiations suspended since December 2008.
But Netanyahu has rebuffed US and Palestinian calls to halt the construction of homes for Jews on occupied land in and near Jerusalem, referring to those areas as Jewish neighborhoods no different than those in Tel Aviv.
Mitchell was due to arrive in Israel later on Thursday, Palestinian officials and diplomatic sources said, in another attempt to revive the peace talks.
The Palestinians say they will not attend negotiations with Israel - indirect, US-mediated talks - without a settlement freeze in the West Bank and East Jerusalem, territory the Jewish state captured in the 1967 Middle East war.
The future of an already strained relationship between Obama and Netanyahu could hinge on the outcome of Mitchell's mission. He was last in the area a month ago, just before Netanyahu's White House talks.
Agreement by Netanyahu to curb Jerusalem settlement could heal a split with Obama that has raised fears among Israelis that strategic cooperation with Washington could suffer at a critical juncture in efforts to thwart Iran's nuclear ambitions.
But it also could open cracks in Netanyahu's governing coalition, dominated by pro-settler parties, including his own.
"We hope (Mitchell) will have the right formula for resuming proximity talks by having Israel stop settlement activities," Palestinian chief negotiator Saeb Erekat said.
The Palestinians want East Jerusalem as the capital of a future Palestinian state. Israel regards all of Jerusalem as its capital, a claim that is not recognized internationally.
The United States has called on Israel not to take steps that could predetermine the future of Jerusalem, an issue at the heart of the Middle East conflict.
Palestinians fear that a proliferation of settlement will strip them of territory needed for a viable state.
In a sign of increasing US frustration, Obama's national security adviser, Jim Jones, put both sides on notice in a speech on Wednesday that Iran was "cynically" using their conflict to divert attention from its nuclear program
