Fernando Alonso will miss the Monaco GP to race at the Indianapolis 500 next month.
The double world champion will race for in a Honda-powered McLaren which will be run by the Andretti Autosport team.
"I'm immensely excited that I'll be racing in this year's Indy 500, with McLaren, Honda and Andretti Autosport," Alonso said.
"The Indy 500 is one of the most famous races on the global motorsport calendar, rivalled only by the Le Mans 24 Hours and the Monaco Grand Prix and it's of course a regret of mine that I won't be able to race at Monaco this year.
"I've won the Monaco Grand Prix twice, and it's one of my ambitions to win the Triple Crown [the Monaco Grand Prix, the Indianapolis 500 and the Le Mans 24 Hours], which has been achieved by only one driver in the history of motorsport: Graham Hill.
"It's a tough challenge, but I'm up for it. I don't know when I'm going to race at Le Mans, but one day I intend to. I'm only 35: I've got plenty of time for that."
McLaren will announce who will replace Alonso in Monaco at a later date. Jenson Button is currently under contract as the team's reserve driver.