Israeli opposition chief Isaac Herzog called on Tuesday for a resumption of peace negotiations to prevent a new uprising, after talks with Palestinian President Mahmud Abbas in the West Bank.

"We agreed on the fact that on the ground in recent weeks and days there is a deterioration, there is an escalation in terror activities," he told reporters at the Ramallah headquarters of Abbas's Palestinian Authority.

A Palestinian detainee on a two-month hunger strike emerged from a coma Tuesday but pledged to resume fasting if Israel did not resolve his case within 24 hours, a Palestinian group said. 

Mohammed Allan, 31, "declared in front of his doctors that if there is not any solution to his case within 24 hours he will ask for all treatment to stop and will stop drinking water," the Palestinian Prisoners Club said in a statement.

Israel said Monday it was not engaged in talks with Hamas following a flurry of media reports suggesting the two sides were discussing a long-term ceasefire.

"Israel is officially clarifying that it is not holding any meetings with Hamas, neither directly, nor via other countries or intermediaries," the office of Prime Minister Benjamin Netanyahu said in a statement.

More than 300 American rabbis wrote members of Congress Monday urging them to support the international nuclear deal with Iran, signalling the U.S. Jewish community is split over the historic but controversial accord.

The religious leaders come from across the spectrum, but hail overwhelmingly from Judaism's Conservative and Reform streams as well as other progressive Jewish movements, a spokesperson said.

Israel on Monday offered to free a Palestinian detainee whose two-month hunger strike has left him in a coma -- but only if he goes abroad, a demand his lawyer immediately dismissed.

The justice ministry made its proposal ahead of a hearing at Israel's top court over whether to release Mohammed Allan, 31, who lapsed into a coma on Friday after ingesting only water since June 18.

Israeli security forces shot dead a Palestinian who tried to stab a border police officer in the West Bank on Monday, authorities said, in the fourth such incident in a week.

The Palestinian approached a checkpoint at the Tapuah Junction near Nablus claiming he was sick, then attempted to stab the officer, police spokeswoman Luba Samri said in a statement.

Protesters rallied Monday in support of an Israeli who went missing after crossing into the Gaza Strip in a case that has highlighted concerns over alleged discrimination against Israel's Ethiopian community.

The family of Avraham Mengistu, 28 and of Ethiopian descent, decided to take their campaign public to push for his release after having previously criticised the Israeli authorities over their response to his disappearance.

Arab supporters and Jewish detractors of a Palestinian held by Israel without trial clashed Sunday with police near the hospital treating him after he lost consciousness during a hunger strike.

Police said they arrested more than 10 Jews and Arabs, including Palestinians from east Jerusalem, for throwing stones at officers and disrupting public order in the southern city of Ashkelon where 31-year-old Mohammed Allan is being treated.

The Israeli government on Sunday approved a major deal with a consortium including U.S. firm Noble Energy on natural offshore gas production in the Mediterranean, the prime minister's office said.

The agreement, which was announced on Thursday and is expected to face a parliamentary vote, aims to end months of uncertainty and set a framework for the exploitation of gas discoveries.

A Palestinian held by Israel without trial has slipped into a coma after a nearly two-month hunger strike, his lawyer said Friday, raising fears for his life.

"I was informed yesterday (Thursday) evening by the (Israeli) hospital where he is being held that he had fallen into a coma," Jamil al-Khatib, 31-year-old Mohammed Allan's attorney, told AFP.