A former U.S. ambassador to South Korea on Monday visited Pyongyang, apparently to try to secure the release of an American detained there, AP Television reported.

Donald Gregg, a former Central Intelligence Agency official who served as Washington’s ambassador to Seoul from 1989-93, was leading a four-member delegation of the Pacific Century Institute, a non-governmental organization based in the Los Angeles area.

The goal of his mission remains unclear, as it coincides with Pyongyang’s cancellation for a second time of its invitation to Robert King, U.S. special envoy for North Korean human rights, to discuss the release of Kenneth Bae.

An official at Seoul’s Foreign Ministry said he had no knowledge of Gregg’s trip.

Bae, a Korean-American tour operator, was arrested in November 2012 in Rason, a special economic zone near the Chinese border, and sentenced in April to 15 years of hard labor for committing “hostile acts” against the North.

Gregg’s trip marks the first trip to the reclusive state by a high-profile U.S. figure in nearly three years, and may pave the way for a restart of bilateral dialogue, observers say.

Speculation aroused that Gregg’s team may have had planned to travel along with King but decided to go alone after Pyongyang scrapped its invitation.

The Pacific Century Institute was set up in Kentucky in the mid-1980s by several American and Korean scholars with the aim of improving international relations between countries and intercultural relations between the Pacific Rim countries, according to its website.

By Shin Hyon-hee (heeshin@heraldcorp.com)