Israeli Prime Minister Benjamin Netanyahu warned Sunday that any nuclear deal leaving Iran with the capability to enrich uranium would be "catastrophic."

"It would be a disaster for the United States and for everyone else," Netanyahu said as a deadline loomed for an agreement on Iran's disputed nuclear program between the West and the Islamic Republic.

British Foreign Secretary William Hague said on Saturday he was "extremely concerned" about the loss of life in Gaza, where five days of Israeli air strikes have killed more than 120 Palestinians.

"Extremely concerned about humanitarian situation and loss of life in Gaza. Speaking to President Abbas today," Hague said on Twitter.

U.S. President Barack Obama on Thursday told Israeli Prime Minister Benjamin Netanyahu he was worried fierce fighting with Hamas in Gaza could escalate, and offered U.S. help to broker a ceasefire.

Obama spoke to the Israeli leader after Israeli warplanes pounded the Palestinian enclave but did not stop militants firing rockets at cities inside the Jewish state, and as global concern over rising Palestinian casualties mounted.

U.N. chief Ban Ki-moon appealed Thursday for a ceasefire between Israel and Palestinian militants, calling on the international community to do everything to halt escalating violence in Gaza.

"It is now more urgent than ever to try to find common ground for a return to calm and a ceasefire understanding," he told an emergency meeting of the U.N. Security Council in New York.

A ceasefire with Hamas militants in Gaza is "not even on the agenda," Israeli Prime Minster Benjamin Netanyahu told a parliamentary committee Thursday, an Israeli newspaper reported.

"I am not talking to anybody about a ceasefire right now," the website of Haaretz newspaper quoted Netanyahu as telling the Knesset's foreign affairs and defense committee.

Israeli warplanes pounded Gaza Wednesday, killing at least 30 people in a major new confrontation with Palestinian militants, as Hamas flexed its firepower and sent thousands running for shelters across Israel.

As the death toll from Israel's two-day Operation Protective Edge reached 57, Palestinian President Mahmoud Abbas accused Israel of committing "genocide" in Gaza.

Israeli Foreign Minister Avigdor Lieberman on Monday ended a 20-month political alliance between his party and the ruling rightwing Likud, although his faction will remain in government.

The decision was announced at a press conference after a bitter dispute between Lieberman and Prime Minister Benjamin Netanyahu over the government's handling of intensifying rocket fire by militants in the Gaza Strip. 

Israeli Prime Minister Benjamin Netanyahu on Monday telephoned the father of an east Jerusalem teenager who was kidnapped and killed last week in a suspected revenge attack by Jewish extremists. 

The brutal murder of Mohammed Abu Khder, 16, on Wednesday has sparked days of clashes between angry protesters and riot police which began in annexed east Jerusalem and have since spread to Arab towns in Israel.

Israeli Prime Minister Benjamin Netanyahu urged his cabinet on Sunday to keep a cool head about how to handle growing tensions in and around the Gaza Strip.

"Experience has proved that at moments like this, we have to act responsibly and with a cool head and not with harsh words and impetuousness," he told ministers, who are fiercely divided over how to respond to mounting militant rocket fire on southern Israel.

A Palestinian teenager was kidnapped and killed Wednesday in an apparent act of revenge for the murder by militants of three Israeli youths, triggering violent clashes in east Jerusalem.

Palestinian leaders denounced the killing, holding Israel responsible and demanding the government of Prime Minister Benjamin Netanyahu act to prevent revenge attacks.