Stephen Bosworth, U.S. Special Envoy for the Democratic People's Republic of Korea (DPRK) left for Pyongyang from the Osan Air Force Base at local time 02:02 p.m. (0502 GMT).
Accompanied by five other members including Sung Kim, U.S. negotiator to the six-party talks, Bosworth is expected to arrive in Pyongyang in about an hour.
Bosworth's trip to Pyongyang is reportedly prioritized in persuading the DPRK back to the six-way nuclear talks.
The U.S. has repeatedly stressed that it is not interested in engaging in any nuclear dialogue besides the six-way talks that involve the U.S., China, Russia, Japan, South Korea and the DPRK.
The U.S. envoy is also committed to reminding the DPRK of the Sept. 19, 2005 Joint Statement agreed upon at the Beijing-based forum, which calls for the nation to abandon its nuclear program in exchange for political and economic incentives.
Despite of heightened attention on the upcoming trip from the international community, local experts and government officials are warning against excessive expectations, local media said.
Considering the trip marks as the first U.S.-DPRK dialogue made since the inauguration of the Obama administration, it is highly unlikely that the trip alone is enough to bring the DPRK back to the multilateral negotiation table, media have said.
It is also uncertain whom the U.S. envoy will be facing at the negotiation table, with media expecting Vice Foreign Minister Kang Sok-ju as his counterpart.
Although media speculate that Bosworth may be carrying a letter from U.S. President Barack Obama, Bosworth's meeting with DPRK top leader Kim Jong-il is not guaranteed as well.
Wrapping up his stay in Pyongyang on Thursday, Bosworth is scheduled to return to Seoul, where he will brief the Seoul government on the result of the trip.
He will fly to Beijing on Friday, and head for Washington on Dec. 15 after visiting Tokyo and Moscow.