The White House began construction of a mixed martial arts combat cage on the south lawn of the presidential residence, ahead of an event to be held next month to celebrate 250 years of United States independence.

Since Monday, dozens of workers have been seen assembling vaulted arches and a stage.

According to computer-generated images that show what the venue will look like, it will have an octagonal-shaped ring surrounded by a metal mesh fence and thousands of seats.

US President Donald Trump has said it will be “the biggest event” the UFC has ever held.

The UFC is considered the largest mixed martial arts company in the world.

Dubbed UFC Freedom 250, the event is scheduled for June 14 (Trump's 80th birthday), and it is estimated that the company will spend about US$60 million on it.

Despite the enormous promotion of the event, it will have as its main course only two fights for championship titles.

Brazilian Alex Pereira will face Frenchman Ciryl Gane for the UFC interim heavyweight belt, while Spanish-Georgian Ilia Topuria will fight current interim champion Justin Gaethje in the lightweight category.

UFC President Dana White said earlier this month that 4,300 people will watch the event from the South Lawn of the White House, most of them members of the Armed Forces, and 85,000 free tickets will be made available for the public to watch the event from nearby Ellipse Park.

The UFC assured that there will be no general sale of tickets to the public.

“I've never seen so many people want something as much as they want those tickets,” Trump said of the lawsuit.

Yes, packages will be sold for VIP guests, which will give them special access to the event.

The UFC did not confirm the cost, but, according to renowned mixed martial arts journalist Ariel Helwani, guests would have to shell out US$1.5 million.

The UFC said it will not make any profits from the event, according to its parent company TKO Group Holdings.

Company president Mark Shapiro described the show as “a long-term investment.”

The White House has hosted sporting and recreational activities in the past, but the UFC event will mark the first time a live professional sporting event has been held there.

The construction of the cage is another of the transformations of the presidential residence promoted by the Trump administration.

Since returning to the White House, Trump has added gold accents to the Oval Office, paved the rose garden to install a patio, renovated the bathroom attached to Lincoln's bedroom and demolished the East Wing to make way for a new ballroom.