The disarmament and accompanying withdrawal of Israeli troops, the size of the reconstruction fund and the flow of humanitarian aid to the war-battered populace of Gaza are among the major questions likely to test the effectiveness of the board in the months ahead.
The meeting in Washington came amid a broader push by Trump to build a reputation as a peacemaker. It also took place as the United States threatens war against Iran and has embarked on a massive military build-up in the region in case Tehran refuses to give up its nuclear program.
The Board's founding membership does not include some key US Western allies concerned about the scope of the initiative.
In a flurry of announcements at the end of a long, winding speech to representatives from 47 nations, Trump said the United States will contribute $US10bn ($A14 bn) to the Board.
He did not say where the money would come from or whether he would seek it from the US Congress.
Contributors to the fund included Kazakhstan, Azerbaijan, United Arab Emirates, Morocco, Bahrain, Qatar, Saudi Arabia, Uzbekistan, and Kuwait, Trump said.
Estimates for rebuilding Gaza, which was reduced to rubble after two years of war, range up to $70bn ($A100bn)
Trump proposed the board last September when he announced his plan to end Israel's war in Gaza. He later made clear the board's remit would be expanded beyond Gaza to tackle other conflicts worldwide, a point he reiterated on Wednesday by saying it would look into "hotspots" around the world.
Trump also said FIFA will raise $US75m ($A106 m) for soccer-related projects in Gaza and that the United Nations will chip in $US2bn ($A2.8 bn) for humanitarian assistance.
The Board of Peace includes Israel but not Palestinian representatives and Trump's suggestion that the Board could eventually address challenges beyond Gaza has stirred anxiety that it could undermine the UN's role as the main platform for global diplomacy and conflict resolution.
"We're going to strengthen the United Nations," Trump said, trying to assuage his critics. "It's really very important."
The meeting came as Trump threatens war against Iran and has embarked on a massive military build-up in the region in case Tehran refuses to give up its nuclear program.
Trump said he should know in 10 days whether a deal with Iran is possible. "We have to have a meaningful deal," he said.
Trump said several nations are planning to send thousands of troops to participate in an International Stabilisation Force that will help keep the peace in Gaza when it eventually deploys.
Indonesia, Morocco, Kazakhstan, Kosovo and Albania have pledged to send troops, while Egypt and Jordan have committed to train police for the efforts.
"We have to get this right. There is no plan B for Gaza. Plan B is going back to war. No one here wants that," said US Secretary of State Marco Rubio.
The plan for the force is to begin working in areas Israel controls in the absence of Hamas disarmament. The force, led by a US general with an Indonesian deputy, will start in Israeli-controlled Rafah, an area that Israeli forces depopulated and demolished during the war. The aim is to train 12,000 police and have 20,000 troops.
Hamas, fearful of Israeli reprisals, has been reluctant to hand over weaponry as part of Trump's 20-point Gaza plan that brought about a fragile ceasefire last October in the two-year Gaza war.
Trump said he hoped use of force to disarm Hamas would not be necessary. He said Hamas had promised to disarm and it "looks like they're going to be doing that, but we'll have to find out."
Israeli Prime Minister Benjamin Netanyahu said in Israel that Hamas will be disarmed one way or the other. "Very soon, Hamas will face a dilemma - to disarm peacefully or disarmed forcefully," he said.
In Gaza, Hamas spokesperson Hazem Qassem said any international force must "monitor the ceasefire and prevent the (Israeli) occupation from continuing its aggression". Disarmament could be discussed, he said, without directly committing to it.
Hamas, which has resumed administration of the ruined enclave, says it is ready to hand over to a US-backed committee of Palestinian technocrats but that Israel has not allowed the group into Gaza. Israel has yet to comment on those assertions.
Nickolay Mladenov, a Bulgarian with a senior role in the Board of Peace, said at the meeting that 2,000 Palestinians have applied to join a new transitional Palestinian police force.
with AP
