The 24-year-old, who was fined for unsportsmanlike conduct at last year's event, has been praised for improved on-court behaviour this season.

He has been in good form, reaching the Australian Open fourth round in January, and also won admirers for his response to the Australian bushfires.

"I've been playing well, so I'm pumped for what's to come," Kyrgios said.

After his Australian Open was ended with defeat by Spanish top seed Rafael Nadal, the world number 39 spoke of having "made progress as a human".

Last year at Queen's, he was fined £13,766 ($17,600) after accusing a line judge of "rigging the game", mocking the umpire and threatening to walk off court, as well as hitting a ball out of the stadium in another match.

The previous year, he had been fined £13,000 ($16,660) for making a lewd gesture with a water bottle at the London tournament.

In September 2019, he was put on a six-month probationary period after being given a suspended 16-week ban and $25,000 (£19,500) fine for "aggravated behaviour" on court.

Kyrgios has responded favourably both on and off the court. In January, he pledged to donate 200 Australian dollars for every ace he hit that month, a gesture which sparked a huge fundraising effort among his fellow professionals.

The main grass-court event at Queen's will run from 15 to 21 June and be live on the BBC.

Kyrgios will be joined by Croatia's Marin Cilic, who said he would love to win a third title there to take his best form into Wimbledon, which starts the following week.

Top-10 players Daniil Medvedev of Russia and Greece's Stefanos Tsitsipas, plus Spanish defending champion Feliciano Lopez, had already confirmed they would be playing at Queen's, while organisers hope Britain's Andy Murray will recover from a pelvic injury in time.