US Secretary of State John Kerry has said he would "evaluate" the next steps in the Middle East peace process with President Barack Obama, warning there are "limits" to Washington's time.
"This is not open-ended," Kerry told a news conference in Rabat, Morocco, on Friday, adding that it was "reality check" time after negative Israeli and Palestinian moves.
Israeli and Palestinian negotiators on Saturday agreed to meet with US envoy Martin Indyk on Sunday, in the first recent sign of a breakthrough in attempts to revive the negotiations before their scheduled end on April 29.
Kerry said it was regrettable that both sides had taken steps recently that were not helpful in promoting peace and ending the decades-long conflict between the two sides.
But Palestinian President Mahmoud Abbas rejected his appeals to withdraw the applications he signed on Tuesday to adhere to 15 international treaties, a Palestinian official cited by the AFP news agency said.
And Benjamin Netanyahu, the Israeli prime minister, ignored appeals to refrain from "unhelpful" tit-for-tat moves, asking officials to draw up a range of tough reprisals, Israeli media reported.
Kerry said that both parties were still willing to talk, but the US would not "sit there indefinitely".
He plans to return to Washington on Friday after a lengthy trip to Europe and the Middle East. Kerry has been conducting more than a year of intensive shuttle diplomacy trying to broker Israeli-Palestinian peace.
On Thursday, Israel announced that it will not release a fourth batch of Palestinian prisoners because of renewed Palestinian efforts to join international organisations.
Israel had promised to free 104 veteran Palestinian prisoners in four tranches, and in exchange, Ramallah pledged to freeze all moves to seek membership in UN organisations until April 2014.
But Palestinians were enraged when Israel refused to release the final 26 prisoners.
As news of the cancellation broke, Palestinians in Gaza fired four rockets into southern Israel, prompting retaliatory air strikes early on Friday by Israel, according to the AFP news agency. No casualties were reported on either side.
Gaza security officials said seven targets were hit by Israel in three locations, including training sites used by the ruling Hamas armed rebel group. The officials - who spoke on condition of anonymity because they were not authorised to talk to the press - said four Hamas members and two others were injured.
Al Jazeera's Nick Shifrin, reporting from Jerusalem, said hundreds of Palestinians had confronted the Israeli army on Friday near the military prison of Ofer, which is south of Ramallah, the West Bank capital, but Israeli forces had fired tear gas and rubber bullets to disperse the protesters.
The protesters were planning to pray by the prison in solidarity with prisoners. At least three Palestinians were injured.