A series of Israeli strikes early on Monday hit Rafah, the city on the southern edge of the Gaza Strip where 1.4 million Palestinians have fled to escape fighting elsewhere in the four-month Israel-Hamas war.

Israel has been signalling its ground offensive in Gaza may soon target the densely populated city on the Egyptian border. On Sunday, the White House said President Joe Biden had warned Prime Minister Benjamin Netanyahu that Israel should not conduct a military operation against Hamas in Rafah without a "credible and executable" plan to protect civilians.

The strikes hit around Kuwait Hospital early on Monday morning, an AP journalist in Rafah said. Some of those wounded in the strikes had been brought to the hospital.

The Israeli military said it struck "terror targets in the area of Shaboura" -- which is a district in Rafah. The military statement said the series of strikes had concluded, without elaborating on the targets or assessing the potential damage or casualties.

Palestinian health officials did not immediately offer any casualty information.

Biden's remarks were his most forceful language yet on the possible operation. Biden, who last week called Israel's military response in Gaza "over the top", also sought "urgent and specific" steps to strengthen humanitarian aid. Israel's Channel 13 television said the conversation lasted 45 minutes.

Discussion of the potential for a ceasefire agreement took up much of the call, a senior US administration official said, and after weeks of diplomacy, a "framework" is now "pretty much" in place for a deal that could see the release of remaining hostages held by Hamas in exchange for a halt to fighting.

The official, who spoke on condition of anonymity to discuss negotiations, acknowledged that "gaps remain" but declined to give details. The official said military pressure on Hamas in the southern city of Khan Younis in recent weeks helped bring the group closer to accepting a deal.

Netanyahu's office declined to comment on the call. Hamas' Al-Aqsa television station earlier quoted an unnamed Hamas official as saying any invasion of Rafah would "blow up" the talks mediated by the US, Egypt and Qatar.

Biden and Netanyahu spoke after two Egyptian officials and a Western diplomat said Egypt threatened to suspend its peace treaty with Israel if troops are sent into Rafah, where Egypt fears fighting could push Palestinians into the Sinai Peninsula and force the closure of Gaza's main aid supply route.

The threat to suspend the Camp David Accords, a cornerstone of regional stability for nearly a half-century, came after Netanyahu said sending troops into Rafah was necessary to win the four-month war against Hamas. He asserted that Hamas has four battalions there.

Over half of Gaza's population of 2.3 million have fled to Rafah to escape fighting in other areas, and they are packed into tent camps and UN-run shelters. Egypt fears a mass influx of Palestinian refugees who may never be allowed to return.

Netanyahu told "Fox News Sunday" that there's "plenty of room north of Rafah for them to go to" after Israel's offensive elsewhere in Gaza, and said Israel would direct evacuees with "flyers, with cellphones and with safe corridors and other things". But the offensive has caused widespread destruction, with little capacity to take in people.

The standoff between Israel and Egypt, two close US allies, took shape as aid groups warned that an offensive in Rafah would worsen the catastrophic humanitarian situation in Gaza. Around 80 per cent of residents have fled their homes, and the UN says a quarter of the population faces starvation.

A ground operation in Rafah could cut off one of the only avenues for delivering food and medical supplies. Forty-four trucks of aid entered Gaza on Sunday, said Wael Abu Omar, a spokesman for the Palestinian Crossings Authority. About 500 entered daily before the war.

WHERE WOULD CIVILIANS GO?

Officials spoke on condition of anonymity because they were not authorised to brief reporters on the sensitive negotiations. Qatar, Saudi Arabia and other countries have also warned of severe repercussions if Israel goes into Rafah.

"An Israeli offensive on Rafah would lead to an unspeakable humanitarian catastrophe and grave tensions with Egypt," European Union foreign policy chief Josep Borrell wrote on X. Human Rights Watch said forced displacement is a war crime.

Israel and Egypt fought five wars before signing the Camp David Accords, brokered by the US, in the late 1970s. The agreement includes provisions governing the deployment of forces on both sides of the heavily fortified border.

Egyptian officials fear that if the border is breached, the military would be unable to stop a tide of people fleeing into the Sinai Peninsula.

The UN says Rafah, normally home to fewer than 300,000 people, now hosts 1.4 million more and is "severely overcrowded".

Inside Rafah, some displaced people packed up again. Rafat and Fedaa Abu Haloub, who fled Beit Lahia in the north earlier in the war, placed their belongings onto a truck. "We don't know where we can safely take him," Fedaa said of their baby. "Every month we have to move."

Om Mohammad Al-Ghemry, displaced from Nuseirat, said she hoped Egypt would not allow Israel to force Palestinians to flee into the Sinai "because we do not want to leave".