JERUSALEM -- Prime Minister Ariel Sharon vowed Monday to press Israel's assault on Hamas, and the militant Islamic group rebuffed proposals for a truce with Israel.
With the peace effort stumbling, Palestinian Prime Minister Mahmoud Abbas went to the Gaza Strip for a desperate push to persuade militants to lay down their arms.
After a week of violence highlighted by Israeli airstrikes aimed at killing Hamas militants and a Hamas suicide bombing in Jerusalem, with dozens of casualties on both sides, there were concerns that further delays and violence could bury the U.S.-backed "road map" to peace and a Palestinian state.
At the core of the problem is the refusal of Hamas and other militant groups to join Abbas in his call for an end to 32 months of violence against Israel.
Mediators from Egypt re-turned to Cairo on Monday after failing to win over the militants -- whose latest demand appears to be a guarantee that Israel will stop its targeted killings of their militants and leaders.
However, Palestinians involved in the talks said Egypt would invite all the factions to Cairo for more talks. Previous rounds in Cairo have not produced results.
After Monday's session, top Hamas official Ismail Abu Shanab said it was premature to talk about a cease-fire. "Now is not a time for truce. It is time for solidarity and standing united against Israeli attacks on our people," he said.
Targeted killings criticized
A source close to the talks said U.S. mediators would press Israel to agree to end the targeted killings, and that if this succeeded, the militant groups would then agree to a truce. The source, who spoke on condition of anonymity, said the Egyptians were asking for a written American guarantee of Israel's commitment on this issue, and on troop withdrawals and other steps implementing the road map.
The State Department underlined that it is not taking part in the Egyptian mediation. "I'm not encouraging their meetings. I'm not sending them out on meetings," spokesman Richard Boucher said in Washington, adding that even if Hamas agrees to a cease-fire the group must be dismantled.
Abbas arrived in Gaza hoping to step up pressure on Hamas, but by late Monday he had not managed to arrange a meeting with the group's leaders, and it appeared the talks would be put off until Tuesday.
Abbas met Monday in Gaza with leaders of his Fatah movement, whose own military wing has also been mounting attacks on Israelis.
Sharon, meanwhile, drew support from President Bush in holding firm against Hamas. Israeli officials insisted they would continue targeting militants and rejected the idea of a cease-fire that did not include a dismantling of the militias, as called for in the road map.
Speaking to the Israeli parliament, Sharon did not mention the cease-fire effort in Gaza and said his government would "pursue and catch every initiator of terrorism and its perpetrators in every place and at every time until victory."
He charged that Hamas had unleashed a "new wave of terror," noting Wednesday's suicide bombing on a Jerusalem bus that killed 17 people. He said Israel would continue targeting terrorists. He noted the recent helicopter strikes also killed Palestinian civilians, but said, "This was not our intention."
Referring to Bush's call for a global cutoff of funds to Hamas, Sharon said, "Because of our position, the voices against Hamas in the world are increasing, and there are calls to increase pressure on this murderous group. This is what we have done, and we will continue to do it."
Sharon repeated his vague offer of "painful concessions" for peace, but added he will "not give anything as long as terror, violence and incitement continue."
Israeli Foreign Minister Silvan Shalom told legislators a cease-fire could not be an end in itself, but "rather a real step to ultimately eliminating the terrorist organizations." Israel opposes a temporary cease-fire, charging that it would simply give the militants a chance to rearm and reorganize.
Hamas condemned Bush's comments, saying in a statement released Monday in Lebanon that his call for action against the militant group amounted to "a new aggression" on the Palestinians.
More than 32 months of violence have killed 2,400 people on the Palestinian side and 801 on the Israeli side. Both sides' economies have been badly hurt, and hatred divides two peoples that only a few years ago seemed on the brink of a peace settlement.
The "road map" -- authored by the United States, European Union, United Nations and Russia -- is a three-stage plan that begins with a halt to violence and is to lead to a Palestinian state by 2005.
Sharon and Abbas both accepted the road map at the June 4 summit in Jordan with Bush, though Israel expressed many reservations.
Among other actions, the Palestinians are required to end violence against Israel, and Israel is to end settlement activity in the West Bank and Gaza, areas the Palestinians want for their state.
On Monday, a senior U.S. official began meetings at the start of a mission to monitor the plan's implementation.
State Department envoy John Wolf met with Shalom in Jerusalem and was due to see Palestinian officials on Tuesday.
Wolf heads a team of monitors who are supposed to determine the level of compliance by both sides to the terms of the peace plan and recommend moving from one stage to the next.