A former U.S. ambassador to South Korea said Friday he expressed "regret" to North Korea over its cancellation of a U.S. envoy's visit regarding jailed American Kenneth Bae and urged the North to release Bae "soon."

"When we heard that he was not going to be released, I expressed regret and said that I hope he would be released soon," Donald Gregg told reporters upon his arrival at Beijing Capital International Airport after wrapping up a five-day visit to North Korea.

Gregg, who heads a U.S. civic group and served as the U.S. ambassador to South Korea from 1989-1993, said the issue of Kenneth Bae was not part of his agenda during this week's trip to Pyongyang. 

Gregg visited Pyongyang a day after the U.S. announced that North Korea had rescinded an invitation for Ambassador Robert King to visit Pyongyang to seek the release of the imprisoned U.S. citizen. 

Bae, 45, has been detained in North Korea for more than a year after being sentenced to 15 years of hard labor on charges of attempting to overthrow the regime. 

"That was not why we went. That was not part of our agenda," Gregg replied, when asked whether his visit was aimed at seeking the release of Bae. 

However, Gregg said he held "very interesting" talks with North Korean officials.

"We had three good meetings," Gregg said, describing the mood as "friendly." He didn't elaborate further.  (Yonhap)