Israel kept up its deadly assault on Hamas-run Gaza on Sunday, prompting Palestinian president Mahmud Abbas to sever all contacts with the Jewish state in a blow to renewed peace talks.

Prime Minister Ehud Olmert vowed to continue the ground and air operation that has killed 70 Palestinians since Saturday and earned Israel international condemnation for disproportionate use of force.

Even Israel’s closest ally the United States called for a halt to the violence and a return to the negotiating table.

Abbas suspended all contacts with Israel over the assault, which apart from killing dozens of militants has also claimed the lives of many Palestinian women and children.

The announcement came just days before US Secretary of State Condoleezza Rice is to arrive in the region on her latest attempt to push forward the troubled peace negotiations revived just three months ago.

“The negotiations are suspended, as are all contacts on all levels, because in light of the Israeli aggression such communication has no meaning,” Abbas’s spokesman Nabil Abu Rudeina said.

The two sides revived peace talks to great fanfare at a conference in the United States in late November, but have made almost no progress since then, while violence in and around the Hamas-ruled Gaza Strip has sharply escalated.

The White House urged both sides to resume the talks.

“The violence needs to stop and the talks need to resume,” National Security Council spokesman Gordon Johndroe told reporters at President George W. Bush’s ranch in Texas.

Seven more Palestinians, including a civilian, were killed on Sunday, medics said, amid the continuing air and ground blitz that Israel says is aimed at halting militant rocket fire at its territory that killed one Israeli civilian last week.

Apart from 63 Palestinians, two Israeli soldiers were also killed in Saturday’s fighting and two more were wounded on Sunday, the army said.

Despite the heaviest offensive since Israel’s Gaza pullout in 2000, militants fired at least 24 rockets at southern Israel on Sunday. Police said one person was injured when his home took a direct hit in the town of Ashkelon.

Late Sunday, Israeli warplanes raided northern Gaza and the Shatti refugee camp where the home of a Palestinian militant was damaged, witnesses said.

Olmert rejected a mounting chorus of international criticism that Israel was using excessive force in one of the world’s most densely populated and impoverished territories.

“We must remember that Israel is protecting its citizens in the south of the country and that with all due respect, nothing will prevent us from this duty,” he said at a weekly cabinet meeting.

In the northern Gaza town of Jabaliya, where Israeli troops operated for a second day in a row, the blasts of improvised mines and Israeli rockets thundered through the air as dozens of tanks lurched through narrow streets.

The Hamas-run administration in Gaza meanwhile called for the formation of an emergency Palestinian unity government eight months after the Islamist movement drove forces loyal to Abbas from the territory.

Defence Minister Ehud Barak was to hold a meeting on Monday to determine the legality of targeting residential areas being used by militants to fire rockets at Israel, his office said.

In the occupied West Bank, thousands of people took to the streets protesting the Israeli blitz and calling for unity.

A 13-year-old Palestinian boy was shot dead by Israeli troops during a demonstration in which youths protesting the Gaza assault threw stones at soldiers, medics said.

The UN Security Council, meeting at Abbas’s request, condemned the violence and urged both sides to respect their obligations under international law.

Members “underscore the need for all parties to immediately cease all acts of violence,” said a statement issued after five hours of hard-nosed talks in New York, which also said the violence should not derail the peace talks.

UN chief Ban Ki-moon slammed Israel’s “disproportionate and excessive use of force,” while EU president Slovenia urged Israel “to exercise maximum restraint and refrain from all activities that endanger civilians.”

At least 304 people have been killed in Israeli-Palestinian violence, most of them Gaza militants, since the relaunch of peace talks in November, 100 of them since Wednesday alone, according to an AFP tally.