Pro-Palestinian demonstrators, holding painted panels, protest outside of the Washington Convention Center in Washington, where the American Israel Public Affairs Committee (AIPAC) is having its annual meeting Sunday, May 22, 2011. (AP Photo/Jose Luis Magana)

Copies of the Al Quds newspaper are displayed in an alley inside Jerusalem's Old City, Monday, May 23, 2011. U.S.-Israel tension over Barack Obama's endorsement of Israel's pre-1967 borders is obscuring a flip side of the Middle East coin: The past days' speeches by the U.S. president contained difficult challenges for the Palestinians as well. Headline reads: 'Al Quds. According to June 4 1967 lines with territory swaps. Obama: Borders of the Palestinian state have to take demographic change into consideration. US President warned Israel about postponing a settlement in the conflict with Arab countries.' (AP Photos/Bernat Armangue)

Palestinian labourers work at a construction site in the West Bank Jewish settlement of Modiin Illit May 23, 2011. REUTERS/Nir Elias (WEST BANK - Tags: POLITICS BUSINESS CONSTRUCTION)

An Israeli soldier watches Palestinian refugees crossing the war-wretched Allenby Bridge to reach the east bank of Jordan in 1967. The June 1967 war was a stunning military victory for Israel, but the start of a political stalemate that continues to this day. (AFP/File)

A Palestinian leans on a donkey as he herds camels on a hill near the West Bank Jewish settlement of Maale Adumim, seen in background May 24, 2011, close to where settlers plan to build a new outpost in reaction to a call from U.S. President Barack Obama in a speech last week for Israel to withdraw to borders from before a 1967 Middle East war as a basis for a peace deal with the Palestinians. REUTERS/Ronen Zvulun (WEST BANK - Tags: POLITICS ANIMALS)

A Palestinian man walks along Israel's separation barrier, in the West Bank town of Aram, as a taxi drives in the east Jerusalem neighborhood of Beit Hanina, Tuesday, May 24, 2011. Israeli prime minister Benjamin Netanyahu is to sketch his vision of Israeli-Palestinian peace before a sympathetic U.S. Congress on Tuesday, after reopening a dispute with President Barack Obama over the contours of a future Palestinian state. (AP Photo/Bernat Armangue)

Israeli soldiers stand guard as Palestinian youths wait to cross to Israel, at the Azun checkpoint near the West Bank Jewish settlement of Elkana, near Nablus, Tuesday, May 24, 2011. Israeli prime minister Benjamin Netanyahu is to sketch his vision of Israeli-Palestinian peace before a sympathetic U.S. Congress on Tuesday, after reopening a dispute with President Barack Obama over the contours of a future Palestinian state. (AP Photo/Ariel Schalit)

Palestinian workers wait in line to cross back after working in Israel, at the Azun checkpoint near the West Bank Jewish settlement of Elkana, near Nablus, Tuesday, May 24, 2011. Israeli prime minister Benjamin Netanyahu is to sketch his vision of Israeli-Palestinian peace before a sympathetic U.S. Congress on Tuesday, after reopening a dispute with President Barack Obama over the contours of a future Palestinian state. (AP Photo/Ariel Schalit)

A Palestinian family herd sheep near the settlement of Maaleh Adumim, background, in the West Bank, Tuesday, May 24, 2011. (AP Photo/Bernat Armangue)

A Palestinian man pauses next to Israel's separation barrier as animal cages are seen in the foreground in the West Bank town of Aram, near Ramallah, Tuesday, May 24, 2011. In Tuesday's speech to the U.S. Congress, Netanyahu said Israel wants to keep key parts of the territories it captured in the 1967 Mideast war, including all of east Jerusalem and parts of the West Bank. (AP Photo/Bernat Armangue)

A view of east Jerusalem's Mount of Olives cemetery, foreground, with the golden Dome of the Rock Mosque at the Al Aqsa Mosque compound, known by the Jews as the Temple Mount, seen in the background at the Old City, Tuesday, May 24, 2011. (AP Photo/Bernat Armangue)