JERUSALEM — Palestinian negotiators are sticking to an end of January deadline in talks with Israel despite U.S. calls for flexibility, a Palestinian official said Friday.

The Palestinians say they want to hold Israel to a schedule that might pressure it to come forward with proposals, but the tight time frame could prevent the nascent talks from getting off the ground.

Palestinian and Israeli negotiators met last week for the first time in more than a year, kicking off low-level contacts aimed at reviving formal peace negotiations.

Disagreements have already emerged, including the deadline for progress in the initial discussions.

Nabil Abu Rdeneh, an aide to Palestinian President Mahmoud Abbas, said Friday that Palestinians will consider halting the talks if no progress is reached by Jan. 26.

"The 26th of January is still a crossroads," he said.

That date was set in October by the Quartet of Mideast negotiators — the U.S., U.N., E.U. and Russia — calling for proposals from each side on the issues of territory and security within three months.

But Israeli officials say the three-month period began only with the first meeting of the negotiators Jan. 3 in Amman, Jordan.

In a bid to soften the Palestinian stance over the date, the State Department said Thursday it did not want the deadline to be final.

"Although this Jan. 26 date has been out there, we do not want to see it be a rigid sort of straitjacket which chills the atmosphere," State Department spokeswoman Victoria Nuland said.

Abbas said Thursday that Israel had so far not made any new proposals at the meetings. Israel, meanwhile, has said the Palestinian proposals were a "recycling" of long-standing positions that Israel opposes.

The talks are set to resume Saturday in Jordan.