American actor Sean Penn has given a bizarre performance during an interview on The Late Show, smoking a cigarette and admitting he was under the influence of sleeping pills.

While speaking to host Stephen Colbert on Tuesday, the 57-year-old appeared tired and was slurring his words, revealing he had recently taken the sedative Ambien to get to sleep after a late-night flight.

“You’ve inherited a little of the Ambien I had to take to get to sleep after a red eye last night,” Penn told Colbert.

Colbert, 53, sought to clarify, asking: “So in others words, you’re still a little bit on the Ambien train right now? Okay.”

Colbert pointed out that Penn is not known for being particularly exuberant even without sedatives.

“I’ve interviewed you before,” he said to the actor. “How do you tell Sean Penn on Ambien from Sean Penn not on Ambien? Because you’re very low-key.”

Penn responded by pulling a cigarette from his pocket and lighting it, before admitting, “It’s pretty much the same.” Thankfully, Colbert had an ashtray on hand because he’d had a “head’s up” the actor might smoke.

Penn, who has won two Best Actor Oscars, was there to discuss his new fictional book, Bob Honey Who Just Do Stuff: A Novel, which reportedly tackles everything from US president Donald Trump to the #MeToo movement, receiving dismal reviews in the process.

While a Washington Post literary critic urged Penn to “never quit your day job” after reading the novel, the spaced-out actor spoke to Colbert about his desire to do less acting.

“As I get older, the greatest thing an actor can bring to the party is to play well with others, it’s the collaboration. I increasingly don’t play well with others, so it becomes less enjoyable,” he explained.

“I love that process when I love it but I’m not loving that anymore. And that’s why I finally came around to writing a novel, because I didn’t have any collaborators – I was never disappointed with me.”

Penn also suggested the rise of streaming service Netflix was one of the reasons he turned to writing books and away from making movies.

“There’s so much content, I can’t keep track of it and nothing feels special,” Penn said.

“So you’re blaming this on Netflix?” Colbert asked.

“Yeah,” Penn replied.

The star’s last movie appearance was voicing a character in the 2016 animated Angry Birds Movie, but he is best known for his performances in films Milk, Mystic River and I Am Sam.

Bob Honey Who Just Do Stuff: A Novel is based on an audio book of the same name that Penn released in 2016 but claimed at the time he had not written.

It was described by The Huffington Post as “reminiscent of a fever dream” that reads like it was written by a “postmodern literature bot”.

“It’s nonsensical, unpleasant and left me sweaty with mingled horror and confusion,” reviewer Claire Fallon wrote.