Biden says 'alarming' Gaza aid deaths complicate ceasefire talks

US President Joe Biden said Thursday that a deadly incident at a food aid point in Gaza would complicate ceasefire negotiations, but also underscored the urgency for a deal between Israel and Hamas.

Biden added that a ceasefire was unlikely to happen by Monday as he previously believed, but stressed he was still hopeful for a deal that would provide a six-week pause in fighting in exchange for the release of hostages held by the Palestinian militant group.

"Hope springs eternal," Biden told reporters at the White House when asked about the ceasefire timing. "I was on the telephone with people in the region... Probably not by Monday, but I'm hopeful."

Biden was also asked about the incident in Gaza, when Israeli forces opened fire on Palestinians scrambling for food aid in a chaotic melee that the health ministry in the Hamas-run territory said killed more than 100 people.

"We're checking that right now. There are two competing versions of what happened, I don't have an answer yet," Biden said as he headed to his helicopter.

Asked if he was worried whether it would complicate the delicate negotiations for a ceasefire, Biden replied: "I know it will."

The White House later said it had asked close US ally Israel to probe the "tremendously alarming" deaths.

"We think that this latest event needs to be thoroughly investigated," deputy press secretary Olivia Dalton told reporters traveling with Biden to Texas on Air Force One.

"We've been in touch with the government of Israel this morning to gather information and to request that they investigate."

- 'Desperate' -

The US State Department called the situation in Gaza "desperate."

"We will be monitoring that investigation closely and pressing for answers," State Department spokesman Matthew Miller told reporters about the aid trucks incident.

Biden separately spoke to two key regional players on Thursday -- Qatar's emir Sheikh Tamim bin Hamad Al-Thani and Egyptian President Abdel Fattah al-Sisi -- about efforts to reach a ceasefire.

They discussed the "tragic and alarming" aid incident in Gaza, saying it "underscored the urgency of bringing negotiations to a close as soon as possible," the White House said in a statement.

Biden and the two Arab leaders also set out new details of what a ceasefire deal could look like.

"The leaders underscored that the release of hostages would result in an immediate and sustained ceasefire in Gaza over a period of at least six weeks," the White House said.

"They exchanged views on how such a prolonged period of calm could then be built into something more enduring" and agreed to stay in touch over the coming days.

The Israeli military said a "stampede" occurred when thousands of Gazans surrounded a convoy of 38 aid trucks, leading to dozens of deaths and injuries, including some who were run over by the lorries.

An Israeli source acknowledged troops had opened fire on the crowd, believing it "posed a threat."

The Gaza health ministry condemned what it called a "massacre" in Gaza City in which 112 people were killed and more than 750 others wounded.

The incident adds to a Palestinian death toll from the war that the ministry said earlier Thursday had now topped 30,000.

Hamas's October 7 attacks resulted in the deaths of around 1,160 people, mostly civilians, Israeli figures show. Militants also took about 250 hostages, 130 of whom remain in Gaza, including 31 presumed dead, according to Israel.