Ilia Topuria shoves Justin Gaethje at UFC press conference

Ilia Topuria shoved Justin Gaethje in front of the Lincoln Memorial in the final news conference before the UFC's unprecedented show at the White House on Sunday.

After both fighters predicted victory in their unification fight, lightweight champion Topuria, 29, pushed interim title holder Gaethje, who responded by laughing off the incident.

As UFC president Dana White separated the fighters with a wry smile on his face, American Gaethje could be heard saying to Topuria: "Look where we're at, look at this beautiful view and you want to act like an animal?"

Earlier, Georgian-Spaniard Topuria had told 37-year-old Gaethje he was "going to knock his lights out in the first round".

"I know I'm best in the world, in two days we're going to share the same place. I know I'm the best, just prove me wrong if you can," said Topuria.

The news conference was hosted in Washington DC, two days before the event on the White House's South Lawn.

The one-of-a-kind show, called UFC Freedom 250, is taking place on US President Donald Trump's 80th birthday as part of celebrations to mark 250 years of American independence.

The Lincoln Memorial provided an eye-catching backdrop for the fighters, who were provided a guard of honour by the U.S. Army Herald Trumpets before they took their seats.

While there were spiky moments between Topuria and Gaethje, there was little said between France's Ciryl Gane and Brazil's Alex Pereira, who will fight for the interim heavyweight title in the co-main event.

Should Pereira win, he will become the first fighter in UFC history to win belts in three divisions after formerly holding the middleweight and light-heavyweight titles.

Earlier Topuria described Pereira as a GOAT (greatest of all time) for his achievements inside the octagon.

"He's the goat already. One of the goats already, because we have many in this sport. He's going to join that list without any doubt," he said.

The news conference was also interrupted numerous times by American heavyweight Josh Hokit, with Topuria at one point asking the UFC to turn his microphone off.