UN Secretary-General Antonio Guterres said Friday that the Gaza ceasefire and hostage deal "must hold", with just hours to go before an initial phase expires.

His comments came after Hamas called for international pressure on Israel to enter the next phase of the ceasefire, as negotiations were resuming in Cairo.

The truce's first phase is due to expire on Saturday morning, after largely halting more than 15 months of Israeli bombardment on the Gaza Strip.

"The ceasefire and hostage release deal must hold. The coming days are critical. The parties must spare no effort to avoid a breakdown of this deal," Guterres said in New York.

Talks on a second phase had been delayed.

They were supposed to begin 16 days into the first stage.

Hamas said in a statement that "with the end of the first phase of the ceasefire", the group "affirms its full commitment to implementing all the provisions of the agreement in all its stages and details".

The group called for global pressure on Israel "to immediately enter the second phase of the agreement without any delay".

The State Information Service of mediator Egypt said in a statement on Thursday: "The relevant parties have begun intensive talks to discuss the next phases of the truce agreement, amid ongoing efforts to ensure the implementation of the previously agreed understandings".

The UN Secretary-General said Friday he will join an emergency meeting of the Arab League in Cairo next week to discuss the reconstruction of Gaza, as Arab states weigh a post-war plan for the Palestinian enclave to counter US President Donald Trump's proposal.

Arab countries have rejected Trump's idea that the US should take over Gaza and redevelop it as a "Riviera of the Middle East" with its population displaced into Egypt and Jordan.

Guterres said Gaza and the West Bank, including East Jerusalem, must be treated as one and governed by a Palestinian government.

He said Gaza needed to remain "an independent, democratic and sovereign Palestinian state, with no reductions in its territory or forced transfer of its population."

Guterres said he would outline priorities at the March 4 Arab League meeting, including that the ceasefire and hostage deal between Israel and Hamas must hold and that there must be a clear political framework towards Gaza's recovery, reconstruction and lasting stability.

He said he will also seek an urgent de-escalation of the situation in the Israeli-occupied West Bank, where Israeli-Palestinian violence has spiked.

"Tuesday’s Summit is an opportunity for leaders across the Arab world to come together and discuss the elements required to deliver peace and stability in Gaza," Guterres told reporters at the UN.