Egypt’s foreign minister has said a truce between militants from Gaza and Israel will begin at 7pm.
The truce includes end to “assassinations” and “incursions”, will also ease movement of Palestinians, according to an Egyptian source.
Speaking in Cairo, US Secretary of State Hillary Clinton thanks the Egyptian government for mediating and said Egypt’s new government is assuming “responsibility, leadership” in the region.
Earlier, UN Secretary General Ban Ki-moon said that there were “many details to work out” before a ceasefire could be reached to end the conflict between Israel and Palestinian militants in Gaza.
Mr Ban said: “I am particularly concerned about the spiral of violence at the time of intense efforts to reach a ceasefire in Gaza and Israel.”
Speaking after a meeting with Egyptian President Mohammed Mursi, whose country is trying to forge a truce.
He said: “We all know there are many details to work out. But while that happens civilians continue to die.”
Mr Ban condemned an attack on a bus in Tel Aviv that wounded 15 people and said it “makes it all the more urgent to reach an immediate ceasefire”.
A spokesman for Prime Minister Benjamin Netanyahu said the explosion was a terrorist attack. The blast shattered windows on the bus, which was driving on a street that runs alongside Israel’s defence headquarters.
Mr Ban met Mr Mursi in Cairo after meeting Israeli Prime Minister Benjamin Netanyahu and Palestinian President Mahmoud Abbas.
Meanwhile, An Israeli plane has bombed the vacated house of a top adviser to Hamas’s prime minister, according to local residents in Gaza.
In an eight-day-old bombing campaign, Israel has hit numerous government buildings operated by Hamas, and has also targeted countless militants.
But it had previously spared Hamas’s political hierarchy, locals said.
An Israeli warplane first fired a warning missile towards the house of Essam al-Daalees, who works closely with Gaza Prime Minister Ismail Haniyeh.
Shortly afterwards it scored a direct hit on the building, in the Nusseirat refugee camp in central Gaza, flattening the property.
Medics reported that one passerby was wounded, adding that the house had been evacuated earlier.
Israel said it launched the offensive to halt repeated rocket attacks out of the coastal enclave.
Some 139 Palestinians have died in the violence, more than half of them civilians, while four Israel civilians and one soldier have also died.
Ceasefire efforts
Egypt is mediating truce talks and had floated hopes for a ceasefire by late last night.
After talks in Ramallah with Palestinian President Mahmoud Abbas and a possible second meeting with Mr Netanyahu, whom she saw late last night, US Secretary of State Hillary Clinton planned to fly to Egypt
Hamas leaders in Cairo accused Israel of failing to respond to proposals and said an announcement on holding fire would not come before daylight.
Israel Radio quoted an Israeli official saying a truce was held up due to “a last-minute delay in the understandings between Hamas and Israel”.
An initial halt to attacks may, however, not see the sides stand their forces down immediately.
Mrs Clinton, who flies to Cairo to see Egyptian President Mohamed Mursi later today, spoke of a deal “in the days ahead”.
As she arrived in Israel after nightfall, Israel was stepping up its bombardment from air and sea. At one point munitions were fired into Gaza at a rate of one every ten minutes.
Gazan rocket fire waned overnight but resumed before dawn with six launches, Israel said. No one was hurt.
Over the past week over 130 Palestinians and five Israelis have been killed.
Both sides are looking for more than a return to the sporadic calm that has prevailed across Gaza since Israel ended an air and ground offensive four years ago.
Mr Netanyahu told Mrs Clinton he wanted a “long-term” solution.
Failing that, Mr Netanyahu made clear, he stood ready to step up the military campaign to silence Hamas’ rockets.
Mrs Clinton assured Mr Netanyahu of “rock-solid” US support for Israel’s security, spoke of seeking a “durable outcome” and of Egypt’s “responsibility” for promoting peace.
“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,” Mrs Clinton said.
“It is essential to de-escalate the situation in Gaza. The rocket attacks from terrorist organisations inside Gaza on Israeli cities and towns must end and a broader calm restored,” she said.