Former U.S. president Jimmy Carter receives a child's salute upon his arrival at the airport in Pyongyang, North Korea, on Wednesday. (Yao Ximeng/Xinhua/Associated Press)

Former U.S. president Jimmy Carter arrived in North Korea's capital Wednesday on a private, humanitarian mission to bring home an American sentenced to eight years of hard labour for trespassing.

A young North Korean girl with a red scarf tied around her neck handed Carter flowers and saluted him after he landed at the Pyongyang airport in an unmarked plane, footage aired by TV news agency APTN showed.

Carter blew her a kiss before getting into a black stretch Mercedes-Benz, according to APTN.

The rare journey to win the release of 31-year-old Aijalon Gomes of Boston comes a year after another ex-president, Bill Clinton, travelled to North Korea on a private mission to bring home two American journalists also sentenced to prison for sneaking into the country illegally. A fourth American was set free earlier this year after 40 days in custody.

As it did with Clinton's visit, North Korea is expected to portray Carter's trip as a diplomatic victory. It comes at a time of heightened tensions over the communist nation's nuclear ambitions and the March sinking of a South Korean warship for which it has been blamed.

Carter shared a warm handshake with the regime's No. 2 official, Kim Yong Nam, before sitting down for talks with him, APTN said.

Senior U.S. officials in Washington confirmed Monday that Carter would be travelling to North Korea to bring back Gomes but stressed that Carter was on a private mission and not representing the U.S. government.

North Korea had agreed to release Gomes, who was believed to be in ailing health, to Carter if the ex-president paid a visit, a senior U.S. official told The Associated Press in Washington. Carter was expected to spend one night in North Korea and return home with Gomes on Thursday, a second U.S. official said.