A Palestinian negotiator has said his side is "less optimistic" about indirect talks with Israel over the Gaza war as a deadline on a temporary ceasefire looms.

The Palestinian team reassembled in Cairo today after members returned from consultations in Qatar, Lebanon and elsewhere in the Middle East. The Israeli team also returned to resume the Egyptian-mediated talks. A current five-day ceasefire is due to end late tomorrow.

The negotiations are aimed at ending the latest war between Israel and Hamas-led Islamic militants in the Gaza Strip and improving conditions for the territory's 1.8 million people. Israel wants guarantees to end rocket fire and attacks on its citizens.

Close to 2,000 Palestinians have been killed - most civilians - and more than 10,000 people have been wounded since the war began on July 8, according to United Nations figures. In Israel, 67 people have been killed, all but three soldiers.

A member of the Palestinian delegation said that the gaps between the sides were still significant and that it was far from certain whether a deal could be reached before the ceasefire expires.

"We are less optimistic than we were earlier," he said.

The negotiator said that a key sticking point remains Hamas's insistence that Israel pledge to end its Gaza blockade before the talks conclude.

Under the terms of an Egyptian proposal, Israel and the West Bank-based Palestinian Authority would negotiate the end to the blockade at some point in the future.

This is the third war in Gaza since Hamas seized power there in 2007. It began after Hamas resumed firing rockets at Israel following the arrests of suspected Hamas-affiliated militants in the West Bank. Israel said the arrests came as part of the investigation into the killing of three Israeli teens in June.