This marks Rodman's fourth trip to the North Korean capital, Pyongyang, where he and his team of fellow former National Basketball Association stars will hold basketball games on Kim's birthday, which is believed to fall on Wednesday, although it has never been officially confirmed.
On previous visits, Rodman spent time dining as a guest of Kim, with whom he says he has a genuine friendship, though he did not meet Kim on his third trip.
Rodman, however, 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," 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," he said of Kim.
"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," he added.
Rodman's latest visit follows the rare public purge of Kim's powerful uncle Jang Song Thaek, who was executed in December.
South Korean President Park Geun-hye has described recent events in North Korea as a "reign of terror."
The purging of Jang, considered the second most powerful man in the north, was widely seen as a sign of factionalism within the secretive government.
The visit also comes as the United States government is trying to secure the release of Kenneth Bae, a Korean-American who worked as a Christian missionary before his arrest by North Korea and conviction in May on charges of crimes against the state.
Rodman has faced both ridicule and harsh criticism from some quarters for his trips, which some US politicians and activists view as serving only as fodder for propaganda efforts by the North Korean regime.
"It's a cruel joke," Eliot Engel, a Democrat in the US House of Representatives and the ranking minority member of the House Foreign Affairs Committee, said at a Monday press conference in New York City.
"There has to be some modicum of behavior before you sit down with people," he said. "The people of North Korea are suffering and we're offering them basketball."
Engel was joined by several North Koreans who have fled the country for political asylum in the United States at the press conference, which was organized by the Simon Wiesenthal Center, a Jewish human-rights group.
"I want to say to NBA player people, please don't make Kim Jong Un happy," said Jo Jinhye, an exiled North Korean now living in Virginia who also runs "NK in USA," an organization that helps fellow exiles.
"If you want to help North Korea," she told reporters, "just help normal North Korean people, not North Korea's government or Kim Jong Un."
At the US State Department, spokeswoman Marie Harf said that Rodman had not contacted the government about his trip.
"He's not there as a representative of the US government trying to effect anything," Harf said. "We were not contacted by him and he's not there representing us."
She also repeated the US government's advice that Americans avoid traveling there.
While in transit at Beijing's airport, the flamboyant Rodman - wearing sunglasses, a sequin-encrusted cap and a pink scarf - 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.
- Politics & Government
- North Korea
- Kim Jong Un