No deal has been reached in Egyptian-mediated talks over Gaza an hour before a 72-hour ceasefire is due to expire and Palestinian factions could reject an extension of the truce under the current terms, a Palestinian source in Cairo said on Friday.

"Negotiations are difficult. Negotiations have not yet reached a final result," said the delegate, speaking on condition of anonymity.

"A rejection of extending the truce is likely. That announcement will come from our brothers in Gaza."

Meanwhile, the armed wing of Hamas called on Palestinian negotiators in Cairo not to extend a 72-hour truce unless their demands, in particular for the opening of Gaza's port, were met and warned it was ready to engage in a long war.

"We urge the Palestinian delegation negotiating not to renew the truce except after the acceptance in principle, particularly to the port (opening), and if there is no acceptance then we ask the delegation to withdraw from talks," a fighter, his face hidden behind a Palestinian scarf, said in a televised statement from Izzedine al-Qassam Brigades.

The statement was aired on the Qatari-owned Al Jazeera news network.

The 72-hour truce is due to end at 0500 GMT on Friday. - Reuters