Lionel Richie has opened up about his upcoming performance in celebration of King Charles III's coronation.

While speaking to Entertainment Tonight on Sunday, the American Idol judge discussed being asked to perform at the British monarch's coronation concert.

"It's an honour," Lionel said of the invitation. "I mean, first of all, when you've been in the business a long time, and, of course, when you get an invitation like this, the answer is absolutely."

The singer continued, "We've been friends a long time, I've known him a long time, but to be asked is the whole thing."

Lionel was appointed the first Global Ambassador for the Prince's Trust, a charity that King Charles III began when he was the Prince of Wales, in 2019. Both he and his American Idol co-star Katy Perry have been set to perform at the coronation concert on 7 May.

"Katy and I are going to represent American Idol. When I tell you that, it's just correct," Lionel gushed. "I mean, we do a lot for the Prince's Trust, so I'm happy to be there."

However, Lionel admitted that "there's more secrecy" surrounding the concert than "you've ever imagined in your life".

"I know what I'm going to do but when you ask, 'What is everyone else going to do?' 'Nothing.' 'Who is everybody else?' 'Hmmm.' 'OK, well, what's the production going to be like?' No response..." he added. "So we won't really know until we get there for the rehearsal to find out exactly how big (it is)."

Take That, Freya Ridings and opera singers Andrea Bocelli and Sir Bryn Terfel will also perform at the coronation concert at Windsor Castle on 7 May, the day after King Charles III's coronation at Westminster Abbey.