South Korea on Wednesday welcomed North Korea's release of one of three American citizens detained in the communist country, calling for Pyongyang to set free other detainees from a humanitarian perspective.

North Korea has released Jeffrey Edward Fowle, who had been detained in the North since April, as he was accused of leaving a Bible in a hotel, the U.S. government said. Fowle was on his way home after leaving the North.

"The Seoul government welcomes the release of Fowle," said an official at Seoul's foreign ministry, asking not to be named. "We hope that North Korea swiftly releases the two other detainees on humanitarian grounds."

The detainment of the three Americans -- Fowle, Kenneth Bae and Matthew Todd Miller -- has posed an impediment to relations between Washington and Pyongyang.

Outside analysts believe that the North is holding the Americans as leverage to force the U.S. to open bilateral talks with it. 

North Korea's surprise move is widely seen as a gesture of goodwill toward the U.S. amid a prolonged standoff in the six-party talks for the denuclearization of the North. But it is not clear about the exact motive behind the North's release of the American citizen. 

"When it comes to the release of Fowle, it seems that there had been no consultations in advance between North Korea and the U.S.," said a high-ranking official at Seoul's foreign ministry.

"It is hard to gauge the North's intention for the move, and it remains to be seen how the North deals with the two other American detainees."

Washington had informed Seoul of its plan to send an airplane to the North in advance before bringing Fowle home, government sources said.

"Communication channels between Seoul and Washington are working smoothly," the official added.

Glyn Davies, the top U.S. nuclear envoy, called on North Korea to release the three detained Americans during his visit to Seoul last month, saying that the issue poses a "serious impediment" to better ties with Washington.

The six-party talks involving the two Koreas, the U.S., China, Japan and Russia have been stalled since late 2008 when the North walked away from the negotiation table.

Pyongyang is now asking for an "unconditional" resumption of the talks, but Seoul and Washington insist that Pyongyang first take concrete steps toward denuclearization. (Yonhap)