The communist nation sentenced the American, Aijalon Mahli Gomes, to eight years of hard labor and a fine of about $600,000 for illegally crossing North Korea's border with China and for an unspecified "hostile act."

"At the request of President Carter, and for humanitarian purposes, Mr. Gomes was granted amnesty by the chairman of the National Defense Commission, Kim Jong-Il," the Carter Center said in a statement. "It is expected that Mr. Gomes will be returned to Boston, Mass., early Friday afternoon, to be reunited with his mother and other members of his family."

The Gomes family plans to issue a statement about the release late Friday morning, said spokeswoman Thaleia Schlesinger.

The U.S. State Department welcomed the development.

"We ... are relieved that he will soon be safely reunited with his family," said department spokesman P.J. Crowley. "We appreciate former President Carter's humanitarian effort and welcome North Korea's decision to grant Mr. Gomes special amnesty and allow him to return to the United States."

The U.S. and North Korea do not have diplomatic relations and as the case of Mr. Gomes illustrates, travel to North Korea is not routine or risk-free," Crowley added.

Two American journalists -- Laura Ling and Euna Lee, who had crossed the border into North Korea in March 2009 and were arrested and sentenced to 12 years hard labor -- were released in August 2009 after an intervention by former U.S. President Bill Clinton.

Carter arrived in Pyongyang Wednesday on a humanitarian mission to negotiate the release of Gomes, believed to be a Christian activist. His visit was a private mission, and was not endorsed by the Obama administration.

Carter was greeted by Kim Gye Gwan, North Korea's chief negotiator at the six-party nuclear talks, and he also met the country's titular head of state, Kim Jong Nam, according to state-run media in North Korea.

"Jimmy Carter made an apology to Kim Yong Nam for American Gomes' illegal entry into [North Korea] and gave him the assurance that such case will never happen again," the Korean Central News Agency reported Friday.

KCNA also reported that Kim told Carter that North Korea wants to resume the so-called six-party nuclear talks and work toward the denuclearization of the Korean peninsula.

There have been hopes of some breakthrough in tense Pyongyang-Washington relations with Carter's visit.

Carter's 1994 talks with the late Kim Il Sung, Kim Jong Il's father, paved the way for the "Agreed Framework" the same year, an agreement designed to rein in Pyongyang's nuclear ambitions.

Wu Dawei, China's vice foreign minister and special representative on Korean Peninsular affairs, has been in Seoul for talks this week with South Korea's Wi Sung-lac. The two men are their country's respective envoys in the currently stalled six-party talks that aim to denuclearize the Korean peninsula.

Wu will also visit Washington, Tokyo and Moscow to brief officials on his recent trip to Pyongyang, a U.S. official told CNN Friday.

But the talks, which started in 2003, have made little progress. North Korea has undertaken two nuclear tests and talks themselves have been in abeyance since 2007.

China has railed against U.S. and South Korean naval exercises held in the eastern Pacific following the sinking of the South Korean warship Cheonan in March, perhaps explaining why Beijing wishes for a resumption of dialogue at this time.

"I think Beijing would like to contain any further escalation of military exercises generated as a result of the Cheonan incident," said Kim Byung-ki, a security expert at Seoul's Korea University. "It is not in their interest to have a further tightening of the U.S.-Korea-Japan alliance."

South Korea, however, may be less willing to resume talks, given the talks' history, and given current public anger over the Cheonan, in which 46 sailors died.

"People I speak to in South Korea say they are not in the mood to return to the table unless there is some kind of apology for the sinking of the Cheonan and some clear signs of a serious implementation of denuclearization commitments," said Dan Pinkston, of the International Crisis Group's Seoul office. "If you are Beijing, how can you demonstrate that North Korea is going to return to the table to bargain in good faith?"