The guests included representatives from tech firms like Amazon, Apple, Meta, Google, Microsoft and Palantir and defence giant Lockheed Martin, according to US media citing a White House guest list.

They also included twins Cameron and Tyler Winklevoss, the founders of crypto platform Gemini who were made famous as jilted investors in the movie “The Social Network” about the birth of Facebook, an AFP journalist in the room saw.

“So many of you have been really, really generous,” Trump told the guests. “I mean, couple of you I have sitting here are saying, ‘Sir, would US$25 million be appropriate?’ I said ‘I’ll take it.'”

Trump has said that the ballroom will be built entirely with private money. It includes US$22 million from a settlement with YouTube in September, after the company suspended his account over the Jan 6, 2021 attack on the Capitol.

Trump opened the curtains of the East Room to show guests where work has started on the giant ballroom, the biggest addition to the White House in more than a century.

He said the building would have four walls of bulletproof glass, a capacity of 1,000 people and be able to host a presidential inauguration – though he didn’t say whose.

It’s the largest in a series of renovations Trump has made to the White House since returning to power in January, including covering the Oval Office with gold decor and paving over the Rose Garden.

Trump also showed the guests his plans for a new project – a huge arch near the Lincoln Memorial in Washington.

He held up a model of the arch – which was dubbed the “Arc de Trump” after it was first revealed in AFP photos last week – and three options for sizes, one of which would be bigger than France’s Arc de Triomphe.

“It’s going to be really beautiful,” Trump added.