Secretary of State Condoleezza Rice said Wednesday the United States is "very concerned" about the plight of the Palestinians and pledged to improve living conditions in the West Bank and Gaza Strip.

Rice, in the region in hopes of reviving long-stalled peace efforts, said the U.S. will "redouble efforts" to help the Palestinians. She spoke after meeting Palestinian President Mahmoud Abbas.

Earlier, Rice called on Islamic militants to cooperate with Abbas, saying the Hamas government cannot govern in the region. She has been seeking to boost Abbas in his standoff with Islamic Hamas radicals who control part of the Palestinian government.

Complete coverage is available in FOXNews.com's Mideast Center.

Reacting, Prime Minister Ismail Haniyeh of Hamas accused the U.S. of trying to "rearrange" the Middle East for its own purposes. Rice "cares only to rearrange this region and to rearrange the Palestinian scene in a way that serves the American and Israeli agenda," Haniyeh said.

Abbas said earlier Wednesday that talks with Hamas on forming a more moderate coalition government have broken down. Abbas also said that a new Cabinet must be formed to end a recent surge in violence that claimed 10 lives in three days. He didn't elaborate.

"There is no dialogue now," Abbas said at a news conference with Bahraini Foreign Minister Sheik Khalid Bin Ahmed Al-Khalifa before Rice arrived.

A preliminary coalition agreement announced Sept. 11 "is over now, and we have to start from square one," he said.

Hamas, which won parliamentary elections in January, refuses to moderate its violently anti-Israel ideology, despite crushing international sanctions.

Before heading to Abbas' headquarters in the West Bank, Rice met with a group of moderate Palestinian politicians in Jerusalem, including members of Abbas' Fatah Party.

One of the participants, Fatah official Kadoura Fares, said he planned to discuss the need for a strong Fatah in the interest of reaching peace with Israel.

Rice is on a Mideast tour this week to strengthen moderate forces in the region, including Abbas.

The meetings came as 135 former world leaders called for "fresh thinking and the injection of new political will" to resolve the conflict between Arabs and Israelis. Signers of the statement, organized by the International Crisis Group, a nonprofit organization based in Brussels, included former President Jimmy Carter and former British Prime Minister John Major.

"As long as the conflict lasts, it will generate instability and violence in the region and beyond," it said.

Rice saw Egypt's longtime leader, President Hosni Mubarak, for a private meeting before she left Cairo for Israel and the West Bank.

She got both a polite hearing and a lecture Tuesday from the United States' two most powerful friends in the Arab world. Saudi Arabia and Egypt both said the Middle East's many volatile conflicts are hinged to Israel's long conflict with the Palestinians.

Arab nations, including the few moderate states that are key to U.S. goals in Iraq, Iran and Lebanon, view improving the Palestinians' lot as essential. They argue that the festering grievances of the stateless Palestinians feed unrest and radicalism elsewhere.

"The issue is how to make peace, and in order to make peace you have to identify the problem," Egyptian Foreign Minister Ahmed Aboul Gheit said during a sometimes strained news conference with Rice.

"We think and we claim and we keep telling everybody that it is the Palestinian problem, and the lack of a settlement for the Palestinians. The Palestinian problem is the scourge of this region," Gheit said.

Saudi Foreign Minister Saud al-Faisal said the nearly 60-year-old conflict was creating a "breeding ground for extremism."

"There is a very short step from extremism to terrorism," Saud said with Rice by his side in Jedda, Saudi Arabia. "And ever since the problem arose of Palestinian-Israeli conflict, the region has been destabilized."

Rice's talks in Ramallah will be the administration's third meeting in less than three weeks with Abbas, whom President Bush called a "man of courage" for trying to revive Mideast peace talks.

Rice wants Saudi Arabia and Egypt to put greater diplomatic muscle behind the moderate Palestinian president in his standoff with Hamas militants, and to bolster moderate secular governments in Lebanon and Iraq.

Rice met in Cairo with diplomats from Egypt and seven other Arab allies in hopes of reviving the moribund Arab-Israeli peace process and making headway on other regional issues. During that session the ministers of the six-nation Gulf Cooperation Council and Egypt and Jordan gave broad support to Abbas, Rice said.

Egypt is a longtime mediator among Palestinian factions and between Israel and the Palestinians, and its exasperation with Hamas may signal a turning point.

Israel wants to reopen dialogue with Abbas and work with him to establish a Palestinian state. But Abbas has been in a weakened position since January when Hamas, which seeks the destruction of Israel, won the Palestinian elections.