“This planned attack against Palestinian civilians would constitute a direct and grave violation of the ceasefire agreement and undermine the significant progress achieved through mediation efforts,” department officials said in a statement shared on the social platform X.

The statement added that if the attack proceeds, the U.S. will take measures “to protect the people of Gaza and preserve the integrity of the ceasefire.”

“The United States and the other guarantors remain resolute in our commitment to ensuring the safety of civilians, maintaining calm on the ground, and advancing peace and prosperity for the people of Gaza and the region as a whole,” the statement concluded.

Following the initial phase of a 20-point peace plan agreed to by Israel and Hamas, with the deal itself overseen by President Donald Trump, Hamas has aimed to reassert its control over Gaza with a wave of retribution executions.

The group has killed at least 33 people as of Tuesday, when the ceasefire went into effect, according to Reuters.

Trump stressed on Tuesday that if Hamas did not lay down their weapons, “we will disarm them.” Should Hamas not follow the peace plan, the Israeli Defense Forces (IDF) are allowed to resume military operations in Gaza.

“Israel has received, via the Red Cross, the bodies of two hostages”, which were returned to Israeli security forces in Gaza, Netanyahu’s office said in a post on the X social media platform early on Sunday.

The prime minister’s office announced that the families of Israeli captives were updated on the return of the remains, and the two bodies had been transferred to Israel’s National Centre of Forensic Medicine for identification.

“The effort to return our hostages is ongoing and will not cease until the last hostage is returned,” the prime minister’s office added.

The Israeli military reported later that one of the bodies was confirmed to be that of Ronen Tomi Engel. The 54-year-old was killed during the Hamas attack on southern Israel on October 7, 2023, and his body was taken to Gaza.

Identification tests are continuing on the second set of remains, the military noted.

With the handover late on Saturday, Hamas has now returned the remains of 12 of the 28 bodies of captives being held in Gaza, a key demand by Israel in the week-old ceasefire deal to end the two-year war.

According to the deal, Hamas was to return all of the Israeli captives – both the living and dead – within 72 hours of its signing. In exchange, Israel was to release 360 bodies of deceased Palestinians and some 2,000 prisoners.

Hamas has stated that the widespread devastation in the Palestinian territory and the Israeli military’s continuing control of certain parts of Gaza have slowed the recovery of the bodies.

For days, Hamas and Israel have traded blame over violations of the US-mediated ceasefire.

On Saturday, Hamas accused the Netanyahu government of “fabricating flimsy pretexts” to not follow through on its commitments to the peace deal, as well as denouncing Israel’s refusal to open the Rafah crossing with Egypt as “a blatant violation” of the agreement.

On Friday, Israeli forces killed 11 members of a single family, including seven children, in an attack east of Gaza City.

The Palestinian Embassy in Egypt announced earlier on Saturday that the Rafah crossing, the main gateway for people in Gaza to leave and enter the enclave, would reopen on Monday.

But Netanyahu announced that the border crossing would remain closed until Hamas hands over the bodies of all the deceased captives.

The delivery of humanitarian aid into Gaza also remains slow despite the ceasefire deal.

Asked if Hamas would give up its arms, Nazzal said: “I can’t answer with a yes or no. Frankly, it depends on the nature of the project. The disarmament project you’re talking about, what does it mean? To whom will the weapons be handed over?”

Arab diplomats previously told Middle East Eye that mediators were in discussions with Hamas about turning its weapons over to Arab peacekeepers or locking up long-range weapons such as missiles instead of destroying them.

US President Donald Trump’s 20-point peace plan calls for Hamas’s demilitarisation. It also calls for a complete staged Israeli withdrawal from the Gaza Strip. The plan doesn’t provide a timeline for either step.

Nazzal stated Hamas will have a “clear” and definitive answer when they get to the negotiating table for phase two of the deal, and that other Palestinian groups would need to be consulted. The Popular Front for the Liberation of Palestine and Islamic Jihad both operate in Gaza.

Nazzal added that Hamas was looking for a three to five-year window for the ceasefire so that Gaza could be rebuilt for civilian purposes. His comments were the first time Hamas has publicly put a timeline on its expectations for the deal, and he was pressed by Reuters whether that prediction meant the group was buying time to rearm for another war.

“The goal is not to prepare for the next war – the goal is that we want a truce in which we rebuild the Gaza Strip because the average years needed to rebuild the Gaza Strip is at least five years, and I don’t want to say less or more, but this is the average,” he stated in response to the question.

“The priority for us in this period that we are putting forward is to build the Gaza Strip and return the Gaza Strip to normal civilian life, this is our priority,” he said.

“But if there are parties that want guarantees for the future after this period of time, then these countries need to offer real hope to the Palestinian people,” he added.

“The Palestinian people want an independent Palestinian state.”

The text of Trump’s 20-point plan says that Hamas will have no role in Gaza’s future governance, but offers members amnesty.

It calls for a body of technocratic Palestinians to run Gaza, overseen by a so-called “board of peace” chaired by Trump. The plan includes some soft language that says the Palestinian Authority may take over Gaza after unspecified reforms. It provides a brief mention of a potential Palestinian state.

On the ground, Hamas has demonstrated that it remains well-organised. Hamas security forces deployed throughout Gaza after the ceasefire. Trump himself said he approved of Hamas deploying to prevent crime, but then said he wanted the group to disarm.

Asked about the deployments, Nazzal said: ”This is a transitional phase. In a civil sense, there will be a technocratic administration as I said. On the ground, Hamas will be present,” he said.

He said after the transitional phase, there should be Palestinian elections.

Hamas has governed Gaza since 2007. Fighting between Hamas and its rival Fatah broke out after the former swept to power in Palestinian legislative elections the year before. In the end, Hamas consolidated its hold over Gaza, and Fatah in the occupied West Bank through the Palestinian Authority.

Reconciliation talks between Fatah and Hamas have been ongoing for years, but there has been little progress on mending ties to potentially stage fresh elections.