Former NBA star and unlikely diplomat, Dennis Rodman, has urged Kim Jong-un to release the American man sentenced to 15 years of hard labour in North Korea, in apparently the first test of their “friendship”.

In a message meant for the young leader sent via Twitter, Rodman called on “the Supreme Leader of North Korea or as I call him ‘Kim’ to do me a solid and cut Kenneth Bae loose”, reports The Associated Press.

Rodman was seen sitting and laughing with Kim during a much-flouted trip to Pyongyang in March where the basketball player pledged his life-long friendship.

The arrest of Kenneth Bae, whose Korean name is Pae Jun-Ho, has raised concerns that the North could use him as a “political pawn” to get concessions from the US in talks over Pyongyang’s nuclear program.

Although the US has sought amnesty for the US citizen sentenced to 15 years of hard labour, Washington said it would not send an envoy to secure Bae’s release.

Bae is at least the sixth American detained in Pyongyang since 2009. The others were eventually deported or released, some after trips to the isolated nation by prominent American officials, such as former presidents Jimmy Carter and Bill Clinton.