Ismail Haniyeh looks on as he arrives for a meeting in Doha, Qatar. Reuters

The leader of Hamas said on Wednesday the group would demand a permanent end to the war in Gaza and Israeli withdrawal as part of a ceasefire plan, dealing an apparent blow to a truce proposal touted last week by US President Joe Biden.

Israel, meanwhile, said there would be no halt to fighting during ceasefire talks, and launched a new assault on a central section of the Gaza Strip near the last city yet to be stormed by its tanks.

The remarks by Hamas leader Ismail Haniyeh appeared to deliver the Palestinian group's reply to the proposal that Biden unveiled last week. Washington had said it was waiting to hear an answer from Hamas to what Biden described as an Israeli initiative.

"The movement and factions of the resistance will deal seriously and positively with any agreement that is based on a comprehensive ending of the aggression and the complete withdrawal and prisoners swap,” Haniyeh said.

Asked whether Haniyeh's remarks amounted to the group's reply to Biden, a senior Hamas official replied to a text message from Reuters with a "thumbs up" emoji.

Washington is still pressing hard to reach an agreement. CIA director William Burns met senior officials from mediators Qatar and Egypt on Wednesday in Doha to discuss the ceasefire proposal.

US President Joe Biden speaks during a press conference. File photo

Since a brief week-long truce in November, all attempts to arrange a ceasefire have failed, with Hamas insisting on its demand for a permanent end to the conflict, while Israel says it is prepared to discuss only temporary pauses until the group is defeated.

Biden has repeatedly declared that ceasefires were close over the past several months, only for no truce to materialise. Notably, Biden said in February that Israel agreed to a ceasefire by the start of the Ramadan Muslim holy month on March 10, a deadline which passed with military operations in full swing.

But last week's announcement came with far greater fanfare from the White House, and at a time when Israeli Prime Minister Benjamin Netanyahu is under mounting domestic political pressure to chart a path to end the eight-month-old war and negotiate the release of Israeli hostages held by Hamas.

Three US officials told Reuters that Biden, having obtained Israel's agreement for the proposal, had deliberately announced it without warning the Israelis he would do so, to narrow the room for Netanyahu to back away.

"We didn't ask permission to announce the proposal," said a senior U.S. official granted anonymity to speak freely about the negotiations. "We informed the Israelis we were going to give a speech on the situation in Gaza. We did not go into great detail about what it was."

Reuters