Ardern told reporters on Monday she would be taking a few days off over the weekend and early next week to recover from the dental operation.
"I apologise; that's more detail than any of you would have liked – and more than I'd like to share, but I didn't want to start any speculation," she told reporters at her weekly post-Cabinet press conference.
The PM appeared in the first segment of Colbert's week-long Newest New Zealander series on his time here.
Ardern also commented on her appearance on the show - in particular, her "Carpool Karaoke" performance.
"Have any world leaders been in touch after your singing segment, to declare war?" asked Vaughan.
"To be fair, Stephen joined me in the massacre of that song," said Arden - but went on to reveal that Colbert is "musically trained."
"He can really sing, he's a beautiful singer," she admitted.
The episode screened here on Tuesday featured Ardern picking up Colbert from Auckland airport then hosting him at a backyard barbecue at her house.
Fletch, Vaughan and Megan were named number one breakfast show for all New Zealanders under 40 in the latest radio audience survey results, announced yesterday.
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