Retired US basketball star Dennis Rodman has arrived in North Korea where he said he was not going to talk about politics or human rights, despite political tension surrounding the execution of leader Kim Jong Un's uncle.

Rodman has visited Pyongyang twice before, spending time dining as a guest of Kim, with whom he says he has a genuine friendship.

His latest visit follows the rare public purge of Kim's powerful uncle Jang Song Thaek, who was executed last week.

South Korean President Park Geun-hye has described recent events as a "reign of terror". The purging of Jang, considered the second most powerful man in the North, indicated factionalism within the secretive Pyongyang government, according to Park.

"It has nothing to do with me," Rodman told Reuters news agency at his hotel in Beijing on Thursday before he left for the airport.

"I mean, whatever his uncle has done, and whoever's done anything in North Korea, I have no control over that. I mean, these things have been going on for years and years and years," Rodman added.

"I'm just going over there to do a basketball game and have some fun," he said.

The US State Department has sought to distance the US government from Rodman's visit.

Ahead of the trip, Seoul-based North Korean human rights activist Shin Dong-hyuk said in an open letter in the Washington Post that Rodman should talk to Kim about human rights abuses in North Korea.

I'm just going over there to do a basketball game and have some fun

Dennis Rodman , former NBA basketball star

Rodman said it was not his place to talk about such issues.

"People have been saying these things here and there. It doesn't really matter to me. I'm not a politician. I'm not an ambassador," he said.

"I'm just going over there to try and do something really cool for a lot of people, play some games and try to get the Korean kids to play," he said.

"Everything else I have nothing to do with. If it happens that he wants to talk about it then great. If it doesn't happen I just can't bring it up because I don't want him to think that I'm over here trying to be an ambassador and trying to use him as being his friend and all of a sudden I'm talking about politics. That's not going to be that way," Rodman said.

Rodman is expected to provide North Korea's national basketball team with four days of training during the trip.

He also intends to return to Pyongyang in January with a team of fellow former National Basketball Association stars to hold basketball games on Kim's birthday.

Rodman's trip was arranged by Irish bookmakers Paddy Power, which has a history of controversial advertising campaigns.

Source: Reuters