A US missionary released by North Korea after entering the communist country on Christmas Day to protest against human rights abuses arrived in China Saturday en route to his homeland, the US embassy said.

North Korean authorities detained Robert Park, 28, for illegal entry after he crossed a frozen border river from China.

He carried a letter calling on leader Kim Jong-Il to free political prisoners, shut prison camps, improve rights and step down.

"We welcome North Korea's release of Robert Park, who arrived in Beijing this morning," said US embassy spokeswoman Susan Stevenson.

"Mr Park is being assisted by embassy consular officers as he prepares to return to the US today. I can't confirm which flight he is on out of respect for his privacy," he added.

Park did not appear before the media in Beijing.

On Friday North Korea's official news agency said he had expressed "sincere repentance" for his actions, which were prompted by "false propaganda" from the West.

"The relevant organ of the DPRK (North Korea) decided to leniently forgive and release him, taking his admission and sincere repentance of his wrongdoings into consideration," said the Korean Central News Agency (KCNA).

The North has said it is also holding an American arrested for illegal entry from China on January 25. That person's motives and identity are unknown and Friday's report did not mention him.

Sanctions-hit North Korea has said it wants better relations with the United States after decades of hostility.

As a condition for returning to stalled multinational nuclear disarmament negotiations, it wants Washington to agree to hold formal peace talks.

A senior Chinese Communist Party official Saturday headed for North Korea, as the international community tries to persuade Pyongyang to return to the nuclear talks, Xinhua news agency reported.

South Korean media said Wang Jiarui was expected to meet North Korean leader Kim Jong-Il and give him a message from President Hu Jintao to help the resumption of the six-party talks which include South Korea, China, Japan, Russia and the United States.

Analysts saw Pyongyang's decision to free Park as an attempt to improve ties as it pushes for dialogue with Washington, which earlier welcomed the decision to free him.

KCNA Friday carried what it said was an interview with Park and issued an undated photograph of him.

"I trespassed on the border due to my wrong understanding of the DPRK caused by the false propaganda made by the West to tarnish its image," the Arizona resident was quoted as saying.

Park was quoted as saying that he had been treated "in a kind and gentlemanly manner" and that "religious freedom is fully ensured" in the North.

He allegedly said he was allowed to pray daily and to attend a service at a Pyongyang church.

"I would not have committed such a crime if I had known that the DPRK respects the rights of all the people and guarantees their freedom and they enjoy a happy and stable life," KCNA quoted Park as saying.

US and United Nations officials, along with international rights groups, have strongly criticised the North's rights record.

"Genuine religious freedom did not exist" in North Korea, according to the US State Department's latest annual rights report.

Jo Sung-Rae, a South Korean activist involved in Park's case, said he did not trust the KCNA interview, saying the American was "speaking under duress."

Last August, former president Bill Clinton met Kim in Pyongyang to secure the release of two US journalists detained for entering the North illegally.

Pyongyang, hit by tougher sanctions for its 2009 nuclear test and missile launches, began making peace overtures to Seoul and Washington after that visit.