TEL AVIV, Jan. 13 -- Israeli military officials said Tuesday that their 18-day offensive in the Gaza Strip had weakened Hamas but that a knockout blow was unlikely. The conflict showed no signs of ending as diplomats reported little progress in negotiating a cease-fire.

The Israeli officials said their strategy was to squeeze Hamas militarily as they try to pressure the Islamist movement into a truce that would include a long-term commitment to stop firing rockets into southern Israel. Some Hamas leaders have said they are willing to cut a deal, but others have pledged to continue fighting.

Despite public vows by Israeli politicians to destroy Hamas's military capability, Israeli officials said Tuesday that the movement had lost only a fraction of its fighters and retained a large stockpile of rockets and other armaments. A "few hundred" Hamas fighters have been killed, out of a total force of 15,000, according to a senior Israeli military official.

In a briefing for foreign journalists, the senior official said Hamas still has hundreds of rockets and other missiles. "We do not see where they have a shortage of personnel to fight," the official said, speaking on the condition of anonymity because he was discussing intelligence matters.

Lt. Gen. Gabi Ashkenazi, the Israeli military chief of staff, said Gaza had been pummeled by more than 2,300 airstrikes since the war began Dec. 27. "We have achieved a lot in hitting Hamas and its infrastructure, its rule and its armed wing, but there is still work ahead," he told the Israeli parliament Tuesday.

For the past several days, Israeli forces have edged closer to Gaza City and other urban centers where Hamas is strongest, but they have held back from an all-out confrontation. Military officials said the goal was to force Hamas into a diplomatic settlement by gradually increasing pressure on the battlefield.

"The issue is, will Hamas agree to stop the firing of rockets into Israel, something they've been doing for eight years?" the senior official said. "This is what we are going after."

Hamas leaders, however, have been split on how to respond. Officials from Gaza have said they are willing to negotiate as long as Israel agrees to withdraw its forces and re-open border crossings that Israel and Egypt closed after Hamas seized exclusive control of the territory in June 2007.

"It is our duty to end the suffering of the Palestinian people," Ghazi Hamid, a Hamas spokesman, told al-Jazeera television Tuesday. "We need to be sure that Israel will respect the cease-fire and not target Gaza again."

But Hamas leaders in exile in Syria have taken a harder line, and it is unclear who is calling the shots.

On Tuesday, Hamas emissaries met in Cairo with Omar Suleiman, Egypt's intelligence chief, who has brokered the negotiations. No breakthroughs were reported. Suleiman later accompanied Egyptian President Hosni Mubarak to Riyadh, Saudi Arabia, to meet with Saudi King Abdullah as Arab leaders tried to coordinate a regional strategy for ending the conflict.

Israel announced that it would send an emissary, Defense Ministry official Amos Gilad, to Cairo on Thursday. Egypt is overseeing the talks in part because Israel refuses to speak directly with Hamas, which it considers a terrorist organization. Israel is also trying to persuade Egypt to accept an international force to help patrol its side of the Gazan border, something officials in Cairo have been reluctant to do.

Israel and Hamas have both rejected a U.N. Security Council resolution calling for an immediate and "durable" cease-fire. On Tuesday, U.N. General Secretary Ban Ki-moon left New York for the Middle East. He is scheduled to visit Egypt, Syria and Jordan in a bid to end the diplomatic impasse.

In Washington, the State Department used unusually strong language Tuesday to deny a claim by Israeli Prime Minister Ehud Olmert that he personally persuaded President Bush to order that Secretary of State Condoleezza Rice abstain on the resolution, which she had negotiated.

Olmert's claim is "wholly inaccurate as to describing the situation, just 100 percent, totally, completely not true," spokesman Sean McCormack said. He said Rice had recommended that the United States abstain.

Israeli military officials said they have focused their combat operations in recent days on the northern part of the Gaza Strip, especially in the suburbs around Gaza City.

Health officials in Gaza said about 960 Palestinians have been killed since the war began, more than half of them civilians. Thirteen Israelis have died, including 10 soldiers. The three others were civilians struck by Hamas rockets.

Israeli military officials said Tuesday that the war has weakened popular support for Hamas in Gaza, which prompted the movement's officials there to send delegates to Cairo for the cease-fire talks. "Their leadership in the Gaza Strip feels the pressure and feels a need to stop the fighting," the senior military official said.

But many Gaza residents interviewed Tuesday predicted that Hamas would bolster its appeal in the long term by standing up to the Israelis. "This crisis was created by Israel and it will create more hatred toward Israel," said Mohamed Ali, 39, a resident of Gaza City. "Who has killed all of our people? Not Hamas. Israel."

While some people expressed anger at Hamas for engaging Israeli soldiers in residential areas, others said the guerrillas had no choice.

"They were born among the people and came from the people," said Tamir Mansour, 35, a clerk at a Gaza City medical clinic. "Gaza is a very narrow, very congested place. We don't have separate camps for the fighters and separate camps for civilians."

Staff writer Glenn Kessler in Washington and special correspondent Reyham Abdel Kareem in Gaza City contributed to this report.