US Secretary of State Hillary Clinton expressed "rock solid" support for Israel's security while calling for a de-escalation of the conflict in Gaza where fighting on Wednesday entered its eighth day, despite signs of an emerging truce.
The top US diplomat flew in for talks with Prime Minister Benjamin Netanyahu as efforts continued across the region to refine an elusive accord to end a week of violence that has cost 136 Palestinian and five Israeli lives.
The Israeli army confirmed its first fatality from rocket attacks on Tuesday, and a civilian contractor working for the defence ministry was also killed, as a longer-range missile landed near Jerusalem and one hit a building in metropolitan Tel Aviv.
The unrelenting violence also claimed the lives of 26 more Palestinians and witnessed an Israeli strike on an eight storey building housing AFP's Gaza City offices, causing no injuries, in the fourth strike on a media building in three days.
In a late-night meeting in Jerusalem, Clinton told Netanyahu that Washington's commitment to Israeli security was "rock solid and unwavering."
But she also stressed that this "is why we believe it is essential to de-escalate the situation" in the Palestinian territory.
And she indicated a truce announcement may not emerge until after she completes visits to the West Bank capital of Ramallah and Cairo for talks with Egyptian President Mohamed Morsi.
"In these days ahead, the United States will work with our partners here in Israel and across the region for an outcome that bolsters security for the peace of Israel, improves conditions for the people of Gaza and moves toward a comprehensive peace for all people of the region," said Clinton.
Hamas sources in Gaza had initially said a deal could be announced in Cairo on Tuesday night following days of Egyptian-brokered negotiations between Israel and Gaza's Hamas rulers.
But Hamas officials said the indirect negotiations were ongoing, as an Egyptian official told AFP in Cairo that "the truce announcement is not expected tonight because we are still waiting for a response" from the Jewish state.
An Israeli diplomatic source told AFP that negotiations were ongoing.
"We are working very hard using our diplomatic channels. We are working continuously. But I cannot give you an estimated time of arrival," at such an agreement, he said.
As they held late night talks in Jerusalem, Netanyahu told Clinton he was ready to agree to a "long-term solution" as long as the rocket attacks from Gaza stopped.
"If there's a possibility of achieving a long-term solution for this problem by diplomatic means, we prefer it. But if not, I'm sure you understand that Israel will have to take every action necessary to defend its people," he said.
A senior Hamas official told AFP in Cairo that a key sticking point was the timing of when Israel would begin easing its six-year blockade of Gaza.
"A compromise solution is for there to be agreement on lifting the siege, and that it would be implemented later at a specified time," he said.
Netanyahu and his key ministers decided in a closed-door meeting late on Monday to place "a temporary hold on a ground incursion to give diplomacy a chance to succeed," as UN Secretary General Ban Ki-moon, after talks in Egypt, urged all parties to end fire "immediately".
Hamas is understood to be seeking guarantees that Israel will stop its targeted killings and end its blockade.
Israel for its part is believed to be looking for a 24- to 48-hour truce as a buffer to work out a more permanent arrangement.
The Security Council held talks late Tuesday to discuss a demand by Arab nations that it hold a public meeting on the crisis, and although Western diplomats expressed fears such a meeting could harm ceasefire efforts, they agreed to meet on Wednesday at 2000 GMT.