US Secretary of State Antony Blinken has begun his Middle East visit in Israel, pledging Washington will rally support to rebuild Gaza as part of efforts to bolster a ceasefire between its Hamas Islamist rulers and Israel.

But Mr Blinken made clear the United States intended to ensure that Hamas, which it regards as a terrorist organisation, did not benefit from the humanitarian aid – a potentially difficult task in an enclave over which it has a strong grip.

Mr Blinken began his regional visit in Jerusalem, where he held talks with Israeli Prime Minister Benjamin Netanyahu.

Mr Netanyahu, speaking to reporters with the top US diplomat at his side, threatened a “very powerful response” if Hamas renewed cross-border rocket strikes.

The truce, brokered by Egypt and co-ordinated with the United States, began on Friday after 11 days of the worst fighting between Palestinian militants and Israel in years.

Now in its fifth day, the truce has been holding.

Israel says it will allow essential supplies and resources into the territory for the first time since May 10. Photo: AP

“We know that to prevent a return to violence we have to use the space created to address a larger set of underlying issues and challenges,” Mr Blinken said.

“And that begins with tackling the grave humanitarian situation in Gaza and starting to rebuild.”

The US, he said, would work to rally international support around that effort and make its own “significant contributions”, to be announced later in the day.

“We will work with our partners, closely with all, to ensure that Hamas does not benefit from the reconstruction assistance,” Mr Blinken said.

In tandem with Mr Blinken’s mission, Israeli authorities said they were allowing fuel, medicine and food earmarked for Gaza’s private sector to enter the territory for the first time since the hostilities began on May 10.

Mr Blinken was also due to meet Palestinian President Mahmoud Abbas in Ramallah in the occupied West Bank later in the day and visit Cairo and Amman.

But US officials have suggested it is too early for wider peace talks between Israel, in political flux after four inconclusive elections in two years, and the Palestinians, divided by enmity between Hamas and the Western-backed Palestinian President.

While the ceasefire is expected to stick, there are concerns fighting will eventually start again. Photo: AP

US President Joe Biden has said a two-state solution is only the way to resolve the Israel-Palestinian conflict.

Gaza counts the cost to rebuild after 11-day war

Hamas, which is regarded by the West as a terrorist group and opposes any Palestinian peace efforts with Israel, began cross-border rocket attacks on May 10, drawing Israeli air strikes.

The hostilities were set off in part by Israeli police raids on the Al-Aqsa mosque compound in Jerusalem and clashes with Palestinians during the Muslim holy month of Ramadan.

At least 253 people were killed in Gaza and more than 1900 injured, Gaza health authorities said, during the heaviest Israeli-Palestinian fighting since a 50-day war in 2014.

The Israeli military put the death toll in Israel at 13, with hundreds treated for injuries after rocket salvoes caused panic and sent people as far away as Tel Aviv rushing into shelters.

Commercial buildings, residential towers and private houses across the Gaza Strip, where two million people live, were damaged or destroyed by the time the ceasefire was announced.

Israel says its air strikes hit legitimate military targets and it did its utmost to avoid civilian casualties, including giving prior warnings when it was about to strike residential buildings that it said also had a military use.

Palestinian officials have put the cost of Gaza’s reconstruction at tens of millions of dollars.

Israel has blockaded the territory since 2007, in what Palestinians condemn as collective punishment.

Egypt also maintains restrictions on its border with Gaza. Both countries cite security concerns for the measures.

–ABC/Reuters