Former NBA basketball player Dennis Rodman has left Beijing for North Korea with a team of retired basketball players to mark the birthday of North Korean leader Kim Jong-un.

This will be Mr Rodman's fourth trip to the North Korean capital Pyongyang, where he and his team of fellow former NBA stars will hold basketball games on Mr Kim's birthday.

As he was interviewed in Beijing airport, Today FM journalist Matt Cooper was seen by his side, prompting speculation he may be accompanying Mr Rodman on the trip.

On previous visits, Mr Rodman spent time dining as a guest of Mr Kim, with whom he says he has a genuine friendship, though he did not meet Mr Kim on his third trip.

Mr Rodman said he will not interfere in the country's politics.

"People always say that North Korea is like a really communist country, that people are not allowed to go there," Mr Rodman told reporters at an airport in Beijing.

"I just know the fact that, you know, to me he's a nice guy, to me."

"Whatever he does political-wise, that's not my job. I'm just an athlete, an individual who wants to go over there and play something for the world. That's it."

Mr Rodman's latest visit follows the rare public purge of Mr Kim's powerful uncle Jang Song-thaek, who was executed in December.

South Korean President Park Geun-hye has described recent events as a "reign of terror".

The purging of Mr Jang, considered the second most powerful man in the North, indicated factionalism within the secretive government.

Wearing sunglasses, a sequin-encrusted cap and a pink scarf, Mr Rodman was asked about his response to critics who said he should not play in the reclusive state.

"Are they going to shoot me? Are they going to shoot me? Come on, man," he said.