JERUSALEM — Efforts to reach a cease-fire between Israel and Hamas intensified Tuesday, but the struggle for even a brief pause in the fighting emphasized the obstacles to finding any lasting solution.
On the deadliest day of fighting in the week-old conflict, Secretary of State Hillary Rodham Clinton arrived hurriedly in Jerusalem and met with Israeli Prime Minister Benjamin Netanyahu to push for a truce. She was due in Cairo today to consult with Egyptian officials in contact with Hamas, placing her and the Obama administration at the center of a fraught process with multiple parties, interests and demands.
Officials on all sides had raised expectations that a cease-fire would begin around midnight, followed by negotiations for a longer-term agreement. But by the end of Tuesday, officials with Hamas, the militant Islamist group that governs Gaza, said any announcement would not come at least until today.
The Israelis, who have amassed tens of thousands of troops on the Gaza border and have threatened to invade for a second time in four years to end the rocket fire from Gaza, never publicly backed the idea of a short break in fighting. They said they were open to a diplomatic accord but were looking for something more enduring.
"If there is a possibility of achieving a long-term solution to this problem through diplomatic means, we prefer that," Netanyahu said before meeting with Clinton at his office. "But if not, I'm sure you understand that Israel will have to take whatever actions necessary to defend its people."
Clinton spoke of the need for "a durable outcome that promotes regional stability and advances the security and legitimate aspirations of Israelis and Palestinians alike."
"In the days ahead, the United States will work with our partners here in Israel and across the region toward an outcome that bolsters security for the people of Israel, improves conditions for the people of Gaza and moves toward a comprehensive peace for all people of the region," she said.
Clinton expressed sorrow for the loss of life on both sides, but called for the Palestinian rocket attacks on Israel to end and stressed that the American commitment to Israel's security is "rock solid."
It was unclear whether she was starting a complex task of shuttle diplomacy or whether she expected to achieve a pause in the hostilities and then head home.
The diplomatic moves came as the antagonists on both sides stepped up their attacks. Israeli aerial and naval forces assaulted several Gaza targets in multiple strikes, including a suspected rocket-launching site near Al Shifa Hospital. That attack killed more than a dozen people, bringing the total number of fatalities in Gaza to more than 130 — roughly half of them civilians, the Gaza Health Ministry said.
A delegation visiting from the Arab League canceled a news conference at the hospital because of the Israeli aerial assaults as wailing ambulances brought victims in, some of them decapitated.
The Israeli assaults carried into early today, with multiple blasts punctuating the otherwise darkened Gaza skies.
Militants in Gaza fired a barrage of at least 200 rockets into Israel, killing an Israeli soldier — the first military casualty on the Israeli side since the hostilities broke out. Israeli officials said a civilian military contractor working near the Gaza border was also killed, bringing the number of fatalities in Israel from the week of rocket mayhem to five.
Other Palestinian rockets hit the southern Israeli cities of Beersheba and Ashdod, and longer-range rockets were fired at Tel Aviv and Jerusalem. Neither main city was struck, and no casualties were reported. One Gaza rocket hit a building in Rishon LeZion, just south of Tel Aviv, injuring one person and wrecking the top three floors.
Senior Egyptian officials in Cairo said Israel and Hamas were "very close" to a cease-fire agreement. "We have not received final approval, but I hope to receive it any moment," said Essam el-Haddad, President Mohammed Morsi's top foreign affairs adviser.
Foreign diplomats who were briefed on the outlines of a tentative agreement said it had been structured in stages — first, an announcement of a cease-fire, followed by its implementation for 48 hours. That would allow time for Clinton to involve herself in the process on the ground here and create a window for negotiators to agree on conditions for a longer-term cessation of hostilities.
But it seemed that each side had steep demands of a longer-term deal that the other side would reject.
Khaled Meshal, the Hamas leader, said in Cairo that Israel needed to end its blockade of Gaza. Israel says the blockade keeps arms from entering the coastal strip.
Mark Regev, a spokesman for Netanyahu, said Israel saw no point in an arrangement that offered Hamas what he called "a timeout to regroup" without long-term guarantees involving the United States and Egypt.
Within Hamas itself, there are divisions and fractured views on the truce negotiations. In Gaza on Tuesday, Fawzi Barhoum, the Hamas spokesman, said that "we hold absolutely no hope of Hillary Clinton" helping to resolve the conflict.
"We hold no hope in Obama or Hillary Clinton to do anything, just to save the occupation in their crisis," Barhoum said in an interview outside Al Shifa Hospital in Gaza City. "Just support the occupation so it can do more and more massacres."
Obama, who was in Asia, had found himself repeatedly on the phone with Middle Eastern leaders in recent days and decided that Clinton, who also spoke to a dozen of her counterparts here, could make the difference in establishing a cease-fire and asked her to make the trip.