Former NBA star Dennis Rodman returned to China from Pyongyang Saturday after a five-day trip when he met North Korean leader Kim Jong-Un, but without jailed American Kenneth Bae.

The flamboyant ex-Chicago Bulls player arrived at Beijing airport on a flight from North Korea, an AFP photographer witnessed, with a cigar clamped in his mouth.

He showed a waiting crowd of reporters dozens of pictures, some of them of him with Kim, the roughly 30-year-old leader of the rogue nuclear-armed state who Rodman describes as his "friend", but quickly became angry, throwing insults before heading to the car park.

"It's not my job to bring him back," he said when asked about Bae.

Earlier Saturday the North's official Korean Central News Agency quoted Kim as saying that Rodman "might visit the DPRK (North Korea) any time and spend pleasant days".

Rodman was reported to have thanked his host for his "expression of good faith towards the Americans" and presented Kim and his wife with a gift. The pair also watched a basketball game together.

There had been speculation that Rodman would try to use his budding relationship with Kim to help free Bae, 45, who was arrested in November 2012 as he entered the hardline communist state's northeastern port city of Rason.

"I'll be back over there. I'm going to try to get the guy out," the heavily tattooed Rodman told celebrity news website TMZ in May.

He also appealed for Bae's release on Twitter, posting: "I'm calling on the Supreme Leader of North Korea or as I call him 'Kim', to do me a solid and cut Kenneth Bae loose."

North Korea, which bans religious proselytising, says that Bae was a Christian evangelist who brought in "inflammatory" material.

He was sentenced to 15 years' hard labour earlier this year on charges of trying to topple the North Korean regime.

Japan's Kyodo news agency quoted Rodman as saying in Pyongyang: "I am sorry about the fact that he (Bae) is in custody and his condition... but I ain't come only for that."

Rodman's entourage for the trip -- which was sponsored by an online gambling firm -- included Michael Spavor, a Canadian who runs an education exchange scheme called the Pyongyang Project, and Joseph Terwilliger, an associate professor of neuroscience at Columbia University in New York.

Terwilliger's webpage on a Columbia site shows him in evening dress playing the tuba, and says he teaches workshops on "Logical Reasoning in Human Genetics".

Kim, who was educated in Switzerland, is reported to be a huge fan of basketball and especially of the Chicago Bulls, with whom Rodman won three NBA titles alongside Michael Jordan in the 1990s.

On a previous visit to North Korea six months ago, Rodman declared himself Kim's "friend for life" and embraced him after the pair watched a basketball game together in Pyongyang.

Rodman faced ridicule from many US commentators over that trip, which came during high tensions over rocket launches and atomic tests by Kim's isolated regime.

At the time, in an enthusiastic commentary on the Kim-Rodman meeting, KCNA quoted Rodman -- nicknamed "The Worm" -- as saying the impasse in US-North Korean relations was "regrettable".

North Korea and the United States have never had diplomatic ties.

A US envoy had been due to travel to North Korea last week to seek Bae's release, but Pyongyang cancelled the invitation at short notice. The North said joint US-South Korean military drills had "beclouded the atmosphere".