US President Donald Trump secured Prime Minister Benjamin Netanyahu's backing for a wide-ranging Gaza peace plan on Monday, as the two leaders warned that Israel would "finish the job" against Hamas if the Palestinian militant group rejects the deal.

Hamas had yet to give its judgment on the proposal that Trump unveiled at the White House alongside Netanyahu, leaving uncertainty swirling around the fate of the 20-point plan to end the war.

The plan calls for a ceasefire, release of hostages by Hamas within 72 hours, disarmament of Hamas and gradual Israeli withdrawal from Gaza, followed by a post-war transitional authority headed by Trump himself.

"I support your plan to end the war in Gaza which achieves our war aims," Netanyahu said in a joint press conference with the US president.

"If Hamas rejects your plan, Mr President, or if they supposedly accept it and then then basically do everything to counter it, then Israel will finish the job by itself."

Trump said that Israel would have his "full backing" to do so if Hamas did not accept the deal. But he insisted peace in the Middle East was "beyond very close" and described the announcement of the plan as a "potentially one of the great days ever in civilisation."

In a sign of the uncertainty, however, the normally talkative Trump said the two leaders would not take questions from reporters as talks with key parties were ongoing.

Trump's plan sparked mixed reactions in a region scarred by nearly two years of devastating war.

A senior Hamas official told AFP that the group would "respond once we receive it." Qatari and Egyptian mediators later shared Trump's proposal with Hamas, another official briefed on the talks said.

Eight Arab or Muslim-majority nations in a joint statement said they "welcome the role of the American president and his sincere efforts aimed at ending the war in Gaza."

They said they "affirm their readiness to engage positively and constructively with the United States and the parties toward finalising the agreement and ensuring its implementation."

The countries include Egypt, Jordan, the United Arab Emirates and Turkey – which all recognise Israel, although some have turbulent relationships.

Also signing the statement were Qatar, which has played a key mediatory role, and Saudi Arabia, whose future normalisation with Israel is a key goal for Trump and Netanyahu.

Indonesia and Pakistan, the world's two most populous Muslim-majority countries, also joined the statement.

The Palestinian Authority, which is based in the West Bank but would be set for a role in a post-war Gaza government, also welcomed Trump's "sincere and determined efforts."

But the deal is full of pitfalls for both Hamas and Israel, while the details could be battled over for weeks or months.

For Hamas, it demands the militants fully disarm and be excluded from future roles in the government, although those who agree to "peaceful co-existence" would be granted amnesty.

But Netanyahu could also face trouble selling the deal to far-right members of his cabinet.

Netanyahu stressed to reporters that Israeli forces would retain responsibility for Gaza security "for the foreseeable future" and cast doubt on the Palestinian Authority's role.

Trump's plan, meanwhile, leaves hope for Palestinian statehood – something he said Netanyahu had strongly objected to during the meeting.

While Trump hailed Netanyahu as a "warrior," he has shown increasing signs of frustration ahead of the Israeli premier's fourth White House visit this year.

Trump was infuriated by Israel's recent strike on Hamas members in key US ally Qatar and he warned Netanyahu last week against annexing the Israeli-occupied West Bank.

During their meeting, Trump arranged for Netanyahu to call Qatar's prime minister from the Oval Office to express "deep regret" for the strike and promise not to do so again, the White House said.

Other key points in Trump's plan include deployment of a "temporary international stabilisation force" – and the creation of the transitional authority headed by him and including former British premier Tony Blair.

Blair, still a controversial figure in much of the Middle East for his role in the 2003 Iraq war, hailed the "bold and intelligent" plan. (AFP)