North Korea said Thursday it was sending diplomats in charge of negotiating with the U.S. up in the political ladder, signaling changes ahead of its ruling party meeting expected to make official the communist regime’s power succession plans.

Kang Sok-ju, the North’s first vice foreign minister, was promoted to vice prime minister, while Kim Kye-gwan, a vice foreign minister and Pyongyang’s chief nuclear negotiator, will succeed Kang, North Korea’s official Korean Central News Agency said.

Ri Yong-ho, also a member of the denuclearization negotiating team, was promoted to vice foreign minister, according to the state media, which did not elaborate on the details of the promotion.

The announcement comes less than a week ahead of North Korea’s purported largest political gathering in 30 years, during which its ailing leader Kim Jong-il is anticipated to give his youngest son Jong-un a key position to pave the way for his succession.

The Sept. 28 convention is the Workers’ Party’s first major gathering since the 1980 meeting when Kim Jong-il was officially named the next leader of the communist state. Building his leadership from then on, Kim eventually took over in 1994 after the death of his father, North Korean founder Kim Il-sung.

Now 68 and reportedly in poor health after apparently suffering a stroke in 2008, the North Korean leader is believed to be preparing to hand over the reclusive regime to his third son.

None of the speculation has been officially confirmed by the North’s media, which rarely unveils what is happening inside the secretive state. Little is known about Jong-un, who is still in his 20s and whose name has never been mentioned in state media.

The North’s largest gathering of party delegates will take place as tensions between the two Koreas appear to be subsiding with Pyongyang releasing a seven-member crew of a South Korea fishing boat, and Seoul responding by sending flood aid and holding talks on resuming reunions of families separated since the 1950-53 Korean War.

Slapped with additional U.S. sanctions earlier this month as punishment for allegedly torpedoing a South Korean warship in March, North Korea has also been showing a renewed willingness to join the stalled six-nation talks over its denuclearization. The North had walked away from the talks at the end of 2008, protesting U.N. sanctions against its second atomic test.

Pyongyang’s promotion of officials related to the nuclear disarmament talks appears to indicate its intent to restart discussing the issue with, in particular, the U.S., one of the partners of the talks that also involve South Korea, China, Japan and Russia.

Kang, the North’s former chief nuclear representative, negotiated the 1994 Pyongyang-Washington Geneva Agreed Framework, which called for freezing of North Korea’s nuclear facilities in exchange for internationally financed light-water reactors. Named the first vice foreign minister at age 47, the veteran diplomat served in the position for 24 years.

Kim, who will be succeeding Kang, was the top North Korean envoy during three rounds of the six-party denuclearization talks from 2005 through 2007. Under the agreements made during these talks, Pyongyang had pledged to dismantle its nuclear facilities in return for aid from the dialogue partners.

Ri, a key member of the North Korean team dealing with negotiations with the U.S. on issues such as nuclear weapons, human rights and missiles, formerly served as Pyongyang’s ambassador to Britain, Belgium and Luxembourg. Returning to the North’s foreign ministry in 2007, Ri is currently the deputy nuclear negotiator.

By Shin Hae-in (hayney@heraldcorp.com)