The White House said that Biden reiterated his “clear position” as Israel plans to invade Gaza’s southernmost city of Rafah despite global concern for more than 1 million Palestinians sheltering there. The U.S. opposes the invasion on humanitarian grounds, straining relations between the allies. U.S. Secretary of State Antony Blinken is returning to the Middle East on Monday.

Biden also stressed that progress in the delivery of humanitarian aid to Gaza is “sustained and enhanced,” according to the statement. It was less stark than their previous call this month in which Biden warned that future U.S. support for Israel in the war depends on swift implementation of new steps to protect civilians and aid workers. There was no comment from Netanyahu's office on the latest call.

A senior official from key intermediary Qatar, meanwhile, urged Israel and Hamas to show “more commitment and more seriousness" in negotiations. Qatar, which hosts Hamas' headquarters in Doha, was instrumental along with the U.S. and Egypt in helping negotiate a brief halt to the fighting in November that led to the release of dozens of hostages. But in a sign of frustration, Qatar this month said that it was reassessing its role.

An Israeli delegation is expected in Egypt in the coming days to discuss the latest proposals in negotiations, and senior Hamas official Basem Naim said in a message to The Associated Press that a delegation from the militant group will also head to Cairo. Egypt’s state-owned Al Qahera News satellite television channel said that the delegation would arrive on Monday.

The comments by Qatar’s Foreign Ministry spokesperson Majed al-Ansari in interviews with the liberal daily Haaretz and Israeli public broadcaster Kan were published and aired Saturday evening.

Al-Ansari expressed disappointment with Hamas and Israel, saying each side has made decisions based on political interests and not with civilians' welfare in mind. He didn't reveal details on the talks other than to say they have “effectively stopped,” with “both sides entrenched in their positions.”

Al-Ansari’s remarks came after an Egyptian delegation discussed with Israeli officials a “new vision” for a prolonged cease-fire in Gaza, according to an Egyptian official, who spoke on condition of anonymity to freely discuss developments.

The Egyptian official said that Israeli officials are open to discussing establishing a permanent cease-fire in Gaza as part of the second phase of a deal. Israel has refused to end the war until it defeats Hamas.

The second phase would start after the release of civilian and sick captives, and would include negotiating the release of soldiers, the official added. Senior Palestinian prisoners would be released and a reconstruction process launched.

Negotiations earlier this month centred on a six-week cease-fire proposal and the release of 40 civilian and sick captives held by Hamas in exchange for freeing hundreds of Palestinian prisoners in Israeli jails.

A letter written by Biden and 17 other world leaders urged Hamas to release their citizens immediately. In recent days, Hamas has released new videos of three captives, an apparent push for Israel to make concessions.

The growing pressure for Hamas and Israel to reach a cease-fire deal is also meant to avert an Israeli attack on Rafah, the city on the border with Egypt where more than half of Gaza’s 2.3 million population is seeking shelter. Israel has massed dozens of tanks and armoured vehicles. The planned incursion has raised global alarm.

“Only a small strike is all it takes to force everyone to leave Palestine," Palestinian President Mahmoud Abbas asserted to the opening session of the World Economic Forum in Saudi Arabia, adding that he believed an invasion would happen within days.

But White House national security spokesman John Kirby told ABC that Israel "assured us they won’t go into Rafah until we’ve had a chance to share our perspectives and concerns with them. So, we’ll see where that goes.”

The Israeli troop buildup may also be a pressure tactic on Hamas in talks. Israel sees Rafah as Hamas’ last major stronghold. It vows to destroy the group's military and governing capabilities.

Aid groups have warned that an invasion of Rafah would worsen the already desperate humanitarian situation in Gaza, where hunger is widespread. About 400 tons of aid arrived Sunday at the Israeli port of Ashdod — the largest shipment yet by sea via Cyprus — according to the United Arab Emirates. It wasn't immediately clear how or when it would be delivered to Gaza.

Also on Sunday, World Central Kitchen said that it would resume operations in Gaza on Monday, ending a four-week suspension after Israeli military drones killed seven of its aid workers. The organization has 276 trucks ready to enter through the Rafah crossing and will also send trucks into Gaza from Jordan, a statement said. It's also examining if the Ashdod port can be used to offload supplies.

* This story was edited by Ahram Online