Washington DC - President Donald Trump rode a ceremonial lap in his armored limousine and waved the green flag to start Sunday's IndyCar race through the streets of Washington, capping celebrations of America's 250th birthday.
Trump, who created the Freedom 250 Grand Prix by executive order as part of the US' anniversary commemoration, had a prime view of the spectacle as open-wheel cars roared past iconic landmarks at speeds up to 185 mph.
"It has turned out to be bigger than we ever thought possible," Trump told race telecaster Fox. "The track is wonderful. I want everyone to be safe and the people to have a good time."
Trump greeted IndyCar series owner Roger Penske (89) and the seven Indianapolis 500 winners in the field of 25 before the 147-lap event began, telling the racers, "Good luck, do well, have fun."
"Roger told me they had been trying to do it for 20 years and when Trump came along they got it done," the 80-year-old president said.
Trump was inside his armored limousine known as "The Beast" as the vehicle and his motorcade slowly took a lap around the 1.7-mile layout, which weaves around such landmarks as the Washington Monument, the National Archives, and Smithsonian museums including the National Gallery of Art.
"The president wanted to do this. He's a big fan. We wanted to be part of the 250th anniversary," Penske said.
"This is really a by-product of our team trying to take it to the next level. This is an iconic race."
Flyovers were next, including ones by a stealth bomber and Air Force One, and air traffic was paused at nearby Reagan National Airport due to the race.
Trump then waved the green flag at the start-finish line in front of the US Capitol building to begin the 250-mile race.
Trump's IndyCar race takes over the streets of DC
"The 100,000 people who will be coming here today, they care about the country," Penske said. "They are excited to see us racing here."
Trump has taken major roles in other events to celebrate the anniversary of the signing of the Declaration of Independence on July 4, 1776, marking the split of 13 original American colonies from Britain.
Among the activities was an Ultimate Fighting Championship bout in a huge cage on the White House lawn in June.
Spanish pole-sitter Alex Palou, a six-time winner this year, can clinch his fourth consecutive IndyCar season title and fifth in six years.
"It's incredible," Palou said of the event. "For sure surpassed all my expectations."
IndyCar and Penske Racing are paying much of the $35 million cost to stage the Grand Prix, supported by sponsors to boost attention for a series best known for the Indianapolis 500 oval classic.
"This is an Indy 500 on the street track," said New Zealand driver Scott McLaughlin.