Stephen Bosworth, U.S. special envoy for the Democratic People's Republic of Korea (DPRK) policies, said on Sunday that his country is prepared for bilateral talks with Pyongyang but such direct dialogue should come only in the context of the six-party process, stressing the necessary of enhancing multilateral cooperation to deal with the nuclear issue on Korean Peninsula.

"We are prepared to engage bilaterally with North Koreans (DPRK) but only within the context of six-party talks," Bosworth told local media after meeting with several South Korean senior officials in Seoul.

The U.S. envoy said that Pyongyang which recently took so- called "two-track" tactic failed to show any fundamental change in its attitude on nuclear issue.

"We are very gratified that young American journalists have been released, but our primary interest remains the denuclearization of the Korean Peninsula, and we continue to ( support) opportunities to reinitiate this process," Bosworth was quoted by Yonhap News Agency as saying.

The DPRK recently made a series of reconciliatory gestures toward the United States and South Korea, such as freeing two detained American journalists during former U.S. President Bill Clinton's trip on Aug 4, and then releasing some South Korean detainees, suggesting holding talks for separated families' reunion, lifting restrictions on inter-Korean border traffic, and restoring a military hotline with South Korea.

But on the other hand, it claimed in a letter to the president of the UN Security Council (UNSC) that the reprocessing of spent fuel rods "is at its final phase and extracted plutonium is being weaponized."

The letter, sent by the permanent representative of the DPRK to the United Nations on Thursday, also said the "experimental uranium enrichment has successfully been conducted to enter into the completion phase. "

Bosworth said the DPRK's uranium enrichment program is "a concern," but he added it is "not the first we've heard of."

Washington and Seoul agreed that the complete and verifiable denuclearization in the Korean Peninsula remains the core of the issue and it requires to be dealt with on a multilateral basis, he said.

On his three-day consultations in Seoul, the U.S. envoy said he was "pleased with the level of coordination" with South Korean partners.

Bosworth arrived here on Friday after concluding a visit to China as part of his three-nation Asia trip. During his stay in Seoul, he met with the South Korean envoy to the six-nation talks Wi Sung-lac, Unification Minister Hyun In-taek and Foreign Minister Yu Myung-hwan. He will fly to Japan late Sunday.

(Xinhua News Agency September 6, 2009)