SEOUL, South Korea — The retired N.B.A. star Dennis Rodman said Monday that on his visit to North Korea last week, the country’s leader, Kim Jong-un, trusted him enough to let him hold his baby daughter and asked him to bring a team of former basketball stars for games in Pyongyang and train the North’s basketball team for the next Olympics.

Mr. Rodman, who had visited Pyongyang once before at the invitation of Mr. Kim, thus solved one mystery about the North Korean leader. Although Mr. Kim’s wife, Ri Sol-ju, was seen pregnant on the North’s state-run television last year, no outsider had reported having seen the baby, much less holding it. In an interview with The Guardian on Sunday, Mr. Rodman called Mr. Kim’s baby “Ju-ae.”

Speaking at a news conference arranged in New York on Monday by Paddy Power, an Irish betting company that helped finance his trip to Pyongyang, Mr. Rodman also revealed that Mr. Kim was 30 years old and that his birthday was Jan. 8. The age and birthday conform with what South Korean intelligence officials have said.

Mr. Kim and Mr. Rodman have forged an odd friendship since the flamboyant N.B.A. legend made his first trip to Pyongyang in February. During that visit, Mr. Kim threw parties for him, and they watched a basketball game together. Mr. Rodman has since publicly professed his affection for his “friend,” Mr. Kim.