Two-time Formula One world champion Fernando Alonso will race in the Daytona 24 Hours for the United Autosports sportscar team next January.
The Spaniard missed the Monaco Grand Prix to compete in the Indy 500 in May and will return to the United States early next year to enter his first endurance event.
Alonso, who last week signed a new contract to remain with McLaren for the 2018 F1 season, will join Phil Hanson and Lando Norris in racing the Ligier JS P217 in the prestigious event which will be staged from January 26-27.
The 36-year-old said: "What an exciting and interesting project. Learning about a completely new racing category, adapting to a different car and to another style of driving and everything that goes with it, is a new challenge for me and I can't wait to test myself again as a driver.
"The Daytona 24 Hours is the most iconic US endurance race and one of the world's great races. Everyone knows it. It's not part of the Triple Crown [Monaco GP, Indy 500 and Le Mans 24 Hours] but, as I have always said, my aim is to be a complete driver and this experience will help me in the preparation for any other endurance race I might take part in.
"Before I went to Indy, I had never driven on an oval, now I know what an oval is and how to deal with it. I am excited to go back and race in America. After the great time I had during the month of May for the Indy 500, I am looking forward to taking part in another legendary race that will bring back all those amazing sensations that US fans gave me.
"Also, this race happens at a convenient time, in January, when our F1 season is off and we are mainly working on our physical preparation. It will be good to get behind a wheel again. Thanks to United Autosports for having offered me this opportunity and thanks to McLaren for supporting me in this new exciting adventure."
Alonso was forced to retire with 21 laps of the Indy 500 remaining after being in contention for victory - the Spaniard having led for 27 laps.
He has endured a frustrating F1 season, securing only 10 points as struggling McLaren have failed to compete with their Honda engines.