"We don't have anything to lose," Erekat said, but suggested there's still a chance to salvage the negotiations.
"The focus now is really, we want to avoid the crash (of the talks), we don't want to undermine the American efforts," he said.
Erekat met earlier Friday with U.S. mediator Martin Indyk.
However, with both sides digging in and Kerry's patience wearing thin, there was no apparent way out. Failed negotiations have in the past led to major bouts of violence and there is growing concern about new bloodshed.
On Friday, several hundred Palestinians threw stones and set tires on fire in a clash with Israeli troops near a West Bank military checkpoint. Troops fired rubber-coated steel pellets and tear gas, lightly injuring five Palestinians, the military said.
In Israel, meanwhile, one of the most outspoken proponents of negotiations with the Palestinians distanced himself from Abbas. Finance Minister Yair Lapid of the centrist Yesh Atid party wrote on his Facebook page that negotiations require two sides interested in a deal.
Abbas' "conduct over the past 24 hours raises serious doubt about whether he is really interested in reaching an agreement," wrote Lapid, whose party is the second largest in Prime Minister Benjamin Netanyahu's center-right coalition.
Earlier Friday, Israeli warplanes struck militant targets in the Gaza Strip hours after Palestinians there fired rockets at Israel. The rocket fire caused no injuries.
Gaza security officials said the Israeli strikes hit seven targets in three locations, including training sites used by the ruling Islamic militant group Hamas militant. Four Hamas members and two others were injured, said the security officials who spoke on condition of anonymity because they were not authorized to talk to the press.
Rocket fire from Gaza has declined since an Israeli campaign in November 2012 that was aimed at ending the then near-daily attacks. Last month, Gaza militants launched the heaviest barrage since that offensive.
Associated Press writer Ian Deitch in Jerusalem contributed to this report.