The mission of U.S. Secretary of State Condoleezza Rice to restart the Palestinian-Israeli peace negotiations was Tuesday facing serious challenges as the Palestinian leadership insisted that Israel first halt its military operations in the Gaza Strip.

Following talks with Rice in Ramallah, Palestinian Authority (PA) President Mahmoud Abbas said he was committed to the peace process, but blamed the Israeli attacks and the siege of Gaza for sabotaging the negotiations.

"I insist on the necessity of installing a comprehensive truce in the Gaza Strip and the West Bank so that we can reach our goal of making 2008 a year of peace," Abbas told reporters. "The choking siege around Gaza has also sabotaged the negotiations. Therefore, I call on the Israeli government to cease its aggression in order to provide the environment necessary for the negotiations."

Rice started her tour in Cairo earlier Tuesday, a day after Israel pulled out its troops from northern Gaza following five days of air and ground assaults that left more than 120 Palestinians killed and hundreds of others injured.

Abbas suspended all contacts with Israel following the intensive military campaign, which Israel said was to stop home-made Qassam rockets being fired at Israel from the Hamas-controlled Gaza Strip. Two Israeli soldiers also died in the operation, dubbed "Hot Winter," which Israel vowed to resume.

Top Palestinian negotiator Ahmad Qurei said when the reasons for which the negotiations were suspended no longer exist, "we will resume the negotiations…. In current circumstances negotiations will lead nowhere."

Hamas, the Islamist movement that overthrew the Fatah-led PA from Gaza last June, as well as other factions, had earlier called on Abbas to resist expected U.S. pressure to resume the talks despite the Israeli escalation, which has also expanded to the West Bank with assassinations and arrests of non-Hamas militants.

Palestinian officials privately told the Middle East Times that Abbas urged Rice to push Israeli leaders, whom she was due to meet later Tuesday and Wednesday, to call off hostilities and open the crossings into the Gaza Strip, which has been a virtual prison since Hamas' takeover.

They said the PA leaders asked Rice for U.S. intervention and guarantees that the Israeli incursions into Gaza and the crackdown on the West Bank would not be repeated.

But the officials added the Palestinians had no illusions that Rice would do anything to press the Israeli government to end military operations, except to urge Tel Aviv to avoid civilian casualties. Reports said at least half of those killed in the latest operation were Palestinian civilians, including 40 children.

"The United States of course understands Israel's right to defend itself," Rice said. "But Israel needs to be very cognizant of the effects of its operations on innocent people. There should be a very strong effort to spare innocent lives."

Palestinian officials, however, were not optimistic that Rice would seek to stop Israel, especially following her remarks in Cairo earlier, in which she held Hamas responsible for the violence and severe living conditions of ordinary Palestinians. She justified the Israeli military response to rocket attacks as self-defense.

"The rocket attacks against innocent civilians in their cities … it needs to stop. No Israeli government can tolerate that," Rice said at the start of her tour.

Rice would not comment on Egyptian efforts to secure a cease-fire between Israel and Hamas, which the U.S. brands as a terrorist group, saying the Islamist organization "is doing what might be expected, which is using rocket attacks on Israel to arrest a peace process in which they have nothing to gain."

Arab commentators said Rice's remarks could be construed as a green light for further Israeli attacks on Gaza, drawing parallels with Rice's failure to demand a truce during the 2006 summer Israeli-Lebanon war.

Nevertheless, Rice expressed optimism that Washington could restart the Palestinian-Israeli negotiations, which formally resumed last November at a U.S.-sponsored conference in Annapolis, Maryland.

"We look forward to the resumption of negotiations as soon as possible," she said, after her hour-long meeting with Abbas, adding she believed that a peace deal could be reached before U.S. President George W. Bush's term expires in January next year.

"I do believe that through engagement, through constant engagement on core issues, that Israeli and Palestinian negotiators … will be able to bring about an agreement" based on a two-state solution, she said.

But independent Palestinian analysts say the Palestinian leadership in Ramallah seems adamant this time about ensuring an end to the Israeli military crackdown in the territories before giving the Americans an image that there is a peace process underway through official meetings between the two sides.

Negotiations since November have basically revolved around the negotiations themselves, rather than dealing with substantive issues to resolve the decades-long conflict, making the process itself an end, not the means, critics say.

With a Palestinian position that so far refuses diplomatic contacts during an Israeli military offensive, and repeated Israeli threats to either re-invade Gaza or resume a fierce offensive, Bush's dream to secure a peace deal before leaving office will probably remain just that – a dream.