Egyptian and Hamas officials said they believed they could reach an agreement to end the week-long Gaza conflict on Tuesday, but a truce hinged on Israeli assent to the Cairo-mediated plan.
The officials were qualifying earlier remarks by Hamas and Islamic Jihad sources who said a truce would be announced Tuesday night, and similar comments by Egypt's President Mohamed Morsi carried by the official news agency.
A senior Egyptian official said there were strong hopes the agreement would be reached by Tuesday night, but that everything depended on Israel giving its assent to the proposal, which had still not come.
Another Egyptian source close to the negotiations said "up to this point there is no final decision."
"Egypt has sent the final proposal... and we are waiting for the final Israeli response," he said. "If there is agreement on this it means we are close to announcing a ceasefire."
An Israeli diplomatic source told AFP that intense negotiations were ongoing but declined to say when or if a deal might be reached.
"We are working very hard using our diplomatic channels. We are working continuously. But I cannot give you an estimated time of arrival (of a truce)," the source said.
Hamas officials had initially sounded a much more upbeat note, speaking of a breakthrough on Tuesday afternoon.
A senior Hamas official told AFP "the agreement is expected to crystallise in a few hours."
But Sami Abu Zuhri, the movement's spokesman in Gaza, later said in a statement that Hamas "has not received the Israeli response and asks all media not to rush."
Zuhri added the Egyptian presidency would make the definitive announcement of an agreement.
The senior Hamas official said the main sticking point was whether Israel would begin easing its six-year long blockade of Gaza coinciding with the truce or at a later date.
"A compromise solution is for there to be agreement on lifting the siege, and that it would be implemented later at a specified time," he said.
The senior Hamas official said Israel had agreed in principle to ease the blockade, which went up when Hamas violently routed its Fatah rivals from the territory.