Former NBA star Dennis Rodman serenaded North Korean leader Kim Jong Un during a basketball game in Pyongyang.

The retired basketball player led an auditorium in singing "Happy Birthday" to Kim, who allegedly turned 31 this week.

North Korean media reported on the event saying Rodman's song quote reflected his reverence for Kim and that Rodman had organised the game as a gift.

This, Rodman's fourth trip to the secluded country, has drawn criticism from human rights activists and the family of U.S. missionary Kenneth Bae- who's imprisoned in North Korea.

During an interview on an American network, Rodman unleashed a string of obscenities and suggested Bae had been responsible for his own incarceration.

Rodman has since issued an apology for his comments saying that he had been drinking and was stressed out.