Prime Minister John Key is going to sell New Zealand to the worldwide tourism market when he appears on a top US television show next month.

Mr Key is booked for the Late Show with David Letterman while he is in New York to speak at the United Nations.

He has a guest appearance on the show's cheeky "Top Ten" slot.

"It's an opportunity to promote New Zealand, it's gold when it comes to New Zealand from a tourism point of view," Mr Key said today.

"This is a show that millions of people watch worldwide, it really is a magnificent opportunity."

Mr Key holds the tourism portfolio and since the election he has focused on attracting more visitors to New Zealand.

"David Letterman is very keen on New Zealand," he said.

"I understand he spent a fair bit of time ribbing Nicole Kidman about how great New Zealand was compared to Australia so I'm sure I'll be able to reinforce her comments."

TV3 News reported his appearance on the show was set up by tourism officials.

- NZPA