By Jeffrey Heller
JERUSALEM (Reuters) - U.S. efforts to save Middle East peace talks from collapse showed little sign of progress on Monday after negotiators met amid threats from Israel to retaliate for what it saw as unilateral Palestinian moves towards statehood.
The U.S.-brokered negotiations plunged into crisis last week after Israel, demanding a Palestinian commitment to continue talking after the end of the month, failed to carry out a promised release of about two dozen Palestinian prisoners.
On Tuesday, Palestinian President Mahmoud Abbas signed 15 global treaties, including the Geneva Conventions on the conduct of war and occupations, on behalf of the State of Palestine, a defiant move that surprised Washington and angered Israel.
Both sides met on Sunday night "to discuss ways to overcome the crisis in the talks," and asked Washington to organize another session on Monday, a U.S. official told Reuters.
An Israeli official described the Sunday session as "business-like" without elaborating. A Palestinian official said his side had submitted conditions for extending the talks beyond the original April 29 deadline for a peace deal.
Palestinians said the signing of the international treaties was a natural progression after the U.N. General Assembly's de facto recognition of a Palestinian state in 2012. They also said they were responding to Israel's failure to free the prisoners.
Palestinians regard brethren jailed by Israel, many for deadly attacks, as heroes in a struggle for statehood. Israel calls them terrorists.
Israeli Prime Minister Benjamin Netanyahu, at a cabinet meeting on Sunday, promised retaliatory measures - which he did not specify - in response to Abbas's move.
The peace talks have struggled since they began in July, stalling over Palestinian opposition to Israel's demand that it be recognized as a Jewish state, and over settlements built on occupied land Palestinians seek for a country of their own.
A senior official in Abbas's Fatah party, said the Palestinians wanted a written commitment from Netanyahu's government recognizing a Palestinian state within all of the territory in the West Bank and Gaza Strip that Israel captured in the 1967 Middle East war, with East Jerusalem as its capital.
Israel has described those West Bank borders as indefensible and considers East Jerusalem as part of its capital, a claim that is not recognized internationally. Israel pulled out of the Gaza Strip, now ruled by Hamas Islamists, in 2005.
In addition, the Fatah official said, Palestinians were demanding a cessation of settlement activity and a prisoner release.
Palestinians fear settlements, viewed as illegal by most countries, will deny them a viable state and have condemned a series of Israeli construction projects announced while talks have been under way.
Stung by his diplomatic setback, just as a complex deal for the negotiations' extension was emerging, U.S. Secretary of State John Kerry has said the United States was evaluating whether to continue its role in the talks, accusing both sides of taking unhelpful steps.
U.S. mediator Martin Indyk has been holding further meetings with both sides.
(Additional reporting by Noah Browning in Ramallah)