It will be Alonso's first attempt at the iconic American event, arguably the most famous motor race in the world. It will also be his first experience of driving on an oval speedway course.

The two-time World Drivers’ Champion will drive a McLaren-entered car run by the Honda-powered Andretti Autosport IndyCar team. Andretti Autosport is headed by Michael Andretti, himself a former McLaren F1 driver.

Alonso’s Indy debut means that he will miss this year’s Monaco Grand Prix.

"I'm immensely excited that I'll be racing in this year's Indy 500, with McLaren, Honda and Andretti Autosport," said Alonso.

"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.

"But Monaco will be the only 2017 Grand Prix I'll be missing, and I'll be back in the cockpit of the McLaren-Honda MCL32 for the Canadian Grand Prix in Montreal in early June."

While the Spaniard has confirmed he'll resume his F1 seat with McLaren after the Indy 500, his one-off Indy deal will heighten the already-growing speculation that he might be gone from McLaren, if not Formula 1 entirely, by the end of this season. His contract with McLaren expires at the end of 2017 and Alonso has repeatedly said that he will not continue in F1 if he feels he does not have access to a competitive car.

At the start of what is Alonso’s third season with McLaren-Honda, there is little sign that the once-mighty team is any closer to developing a competitive package as the Honda engine continues to underperform in comparison to its Renault, Mercedes and Ferrari rivals.

In Indycar racing, Honda is very strong, proving a competitive match for rival engine supplier Chevrolet.