John Lithgow thinks his 'Harry Potter' schedule will be easier than 'The Crown'.

The 79-year-old actor is set to play Album Dumbledore in HBO's upcoming seven-series adaptation of J.K. Rowling's wizard saga, and the American star admitted despite the lengthy commitment, he might not have to be in London as often as he was when he played Winston Churchill on the Netflix period drama between 2016 and 2019.

Asked about his scheduled for 'Harry Potter', he told the 'SmartLess podcast: "I honestly don't know.

"I mean, I was over in England for eight months for 'The Crown' and barely came back [to the US].

"I think I may have come back once or twice. I imagine that I can come back much more."

He noted that he's "halfway through the second" book as he prepares for the project, with "an entire season is devoted to a single novel".

Although he isn't as knowledgeable about the world of Hogwarts as others, what he's learned so far makes him think he won't have to be on set as much as some other cast members.

He said: "Dumbledore is kind of the nuclear weapon.

"He only goes on very, very occasionally. I don't think it's gonna be that hard a job, and, we'll just go back and forth."

However, he admitted taking on such a lengthy role was "a little bit scary".

He explained: "The logistics are a little bit scary. I really did have to think hard about whether to take it on but I also thought, well, I'm about to turn 80 next year.

"If this is indeed a seven or eight-year-long job, it's a wonderful way to grow old as an actor.

"I mean, the alternative is to just be hauled out once a year to play an Alzheimer's patient…and an awful lot of death scenes with weeping middle-aged children, you know."

John recently revealed the casting news in an interview with ScreenRant, and admitted he was "excited" for the project.

He told the outlet: "Well, it came as a total surprise to me. I just got the phone call up at the Sundance Film Festival for yet another film, and it was not an easy decision because it's going to define me for the last chapter of my life, I'm afraid.

"But I'm very excited. Some wonderful people are turning their attention back to 'Harry Potter'.

"That's why it's been such a hard decision. I'll be about 87 years old at the wrap party, but I've said yes."