Former U.S. President Jimmy Carter was expected to arrive in North Korea’s capital city as early as Tuesday to negotiate the release of a U.S. citizen who has been detained since January of this year.

Senior U.S. officials have informed the press of Carter’s plan to depart this week for North Korea on a “purely humanitarian mission” to free 30-year-old Aijalon Mahli Gomes. Gomes, a devout Christian from Boston who taught English in South Korea, was arrested on Jan. 25 and sentenced in April to eight years of hard labor for entering North Korea illegally and for an unspecified "hostile act."

Earlier this month, a team sent by the U.S. State Department to visit North Korea tried to free Gomes but was not granted permission to do so.

North Korea has reportedly requested a visit by a high-profile U.S. figure to gain the release of Gomes, and one U.S. official told The Associated Press that North Korea had agreed to free Gomes if Carter came for him.

Foreign Policy magazine, which first broke the news of Carter’s trip, reported the former president as the top pick among several possible candidates to help secure Gomes’ release. Others who were reportedly considered included Sen. John Kerry (D-Mass.) and New Mexico Gov. Bill Richardson.

Last year, former U.S. President Bill Clinton had flown to Pyongyang to free two U.S. journalists, Euna Lee and Laura Ling of Current TV, who were sentenced to prison after illegally entering North Korea.

At the time, North Korea similarly offered to release their detainees if Clinton came to negotiate their release. The two journalists were consequently freed.