WASHINGTON — President Trump boasted in a speech to world leaders that the Gaza peace agreement could be his “greatest deal” yet — claiming it could end 3,000 years of conflict in the region.

“All I’ve done all my life is deals. The greatest deals just sort of happen,” Trump, 79, said at a celebratory peace-deal signing attended by dozens of nations in Sharm el-Sheikh, Egypt.

“And that’s what happened right here. And maybe this is going to be the greatest deal of them all.”

Trump basked in the praise of prominent NATO allies and Muslim world leaders in the Red Sea resort city after Hamas released 20 Israeli hostages held during the two-year war in exchange for a prisoner release and troop pullback by Israel.

The leaders of France, the UK, Germany, Italy, Canada, Turkey, Qatar, Pakistan, Indonesia, Jordan and Egypt attended the celebration in Egypt, which Trump heralded as about much more than Gaza.

The American leader said permanent peace could be achieved for the first time since the days of David and Goliath.

“From ancient times, this region has been extraordinarily mixed with respect to people, culture, religions and all of the different elements of national characters, unlike maybe anywhere else on Earth,” Trump said.

Follow The Post’s live blog for the latest on the hostage release as Israel-Hamas cease-fire takes effect.

“And for 3,000 years, there’s been conflict. For whatever reason, there’s been tremendous conflict, always conflict. But today, for the first time anyone can remember, we have a once in a lifetime chance to put the old feuds and bitter hatreds behind us.”

With the world’s leaders looking on, Trump signed a document enshrining his 20-point peace plan, with Egyptian President Abdel Fattah el-Sisi, Qatari Emir Tamim ibn Hamad Al Thani, and Turkish President Recep Tayyip Erdogan signing as guarantors.

“It’s so beautiful to see a new and beautiful day is rising, and now the rebuilding begins,” he said, hours after addressing Israel’s Knesset.

“Rebuilding is maybe going to be the easiest part. I think we’ve done a lot of the hardest part because the rest comes together. We all know how to rebuild, and we know how to build better than anybody in the world.”

Trump’s optimistic projections included claims that Iran was interested in reaching its own diplomatic breakthrough improving relations with Washington — four months after the US bombed Tehran’s nuclear sites — and a prediction that more Muslim and Arab countries would establish relations with Israel.

In 2020, Trump’s son-in-law Jared Kushner, who was a leading negotiator in the Gaza talks, spearheaded the Abraham Accords with four Arab nations agreeing to recognize Israel, joining just two others.

“We’re going to get a lot of people joining the Abraham Accords. We have the four great nations that did it early on, and they stayed with it,” Trump said in his Egyptian address.

“And then you had the Biden administration, which is the worst administration in the history of our country. And obviously they did nothing on that and anything else. And so it stayed at four. And now a lot of people, even today, they’re talking about all joining up. So, so many people have talked to me about that, and it’s going to be a great tribute to, really, the United States.”

After Trump finished speaking, he had an extended conversation with Indonesian President Prabowo Subianto, whose government in the past was a target of extending the accords. Indonesia is the world’s most populous Muslim-majority country.

“It’s going to guarantee that it all stays together. And you’re gonna do well, because the four nations do very well,” Trump said of the Abraham Accords.

“They’re wealthy, but they’re a lot wealthier because of it. So I hope everybody’s now joining up now. We have no excuses. We don’t have a Gaza and we don’t have Iran as an excuse.”

“All the momentum now is toward a great, glorious and lasting peace, and our commitment to fulfilling the 20-point plan we developed together will be the crucial foundation for achieving that bright future,” he said.

Trump did not discuss in his public remarks plans for the international peacekeeping force that’s due to enter Gaza, or confirm additional members of the proposed Trump-chaired Board of Peace that will supervise Gaza’s yet-to-be named transitional government.

“This is the first time the Middle East crisis has brought people together, as opposed to driving them apart, and to declare that our future will not be ruled by the fights of the generations past, which is foolish,” Trump instead triumphed.

“So together, let us continue in the spirit of cooperation and goodwill that has finally brought us to this incredible, historic breakthrough.”