North Korea said Wednesday that its ruling Workers' Party of Korea plans to hold its first party congress in more than three decades late next week, a move expected to reaffirm North Korean leader Kim Jong-un's tight grip on power.

The political bureau of the WPK's central committee has decided to open the seventh party congress in Pyongyang on May 6, the Korean Central News Agency said.

It will be the first party congress since October 1980, when the WPK last convened the meeting of the party's highest-level political guidance body. 

The party congress is widely expected to serve as a key event that will reveal the North Korean leader's policy direction in his fifth year in power. Kim inherited power following the sudden death of his father Kim Jong-il in late 2011.

"North Korea is expected to announce the opening of the Kim Jong-un era at the congress," said Yang Moo-jin, a professor at the University of North Korean Studies. "The move will be aimed at cementing the one-man leadership."

The party congress comes amid high tension as North Korea is threatening to carry out another nuclear test and could conduct a mid-and long-range missile test in open defiance of stronger U.N. sanctions.

In March, the U.N. Security Council slapped tougher sanctions on North Korea as punishment for its nuclear test and long-range rocket launch earlier this year.

Since last month, Pyongyang has fired off projectiles and ballistic missiles, warning that it is ready to wage nuclear strikes against Seoul and Washington.

South Korea's unification ministry said that the party congress may last for four to five days, given the North's track record.

"We need to be open to all possibilities in regard to another North Korean nuke test," Jeong Joon-hee, a ministry spokesman, told a regular press briefing. "We are closely watching the situation and ready to take action."

Experts said the congress will be an occasion to reaffirm the leader's commitment to pursuing the leader's signature policy of developing nuclear weapons in tandem with boosting its moribund economy, commonly known as the "byeongjin" policy.

Kim's father advocated a military-first, or "songun," policy, highlighting the role of the National Defense Commission as the main decision-making body.

But the North's current leader has shifted his focus to the WPK while seeking the dual-track policy, which Seoul and Washington view as a dead end.

Analysts said that Pyongyang could unveil new economic policies at the upcoming event, given that Kim is stressing the need to boost the livelihoods of ordinary people.

"The North's leader is focusing on economic development zones and construction works," said Kim Young-hee, head of the team on the North Korean economy at the Korea Development Bank. "There is a possibility that the North may unveil a fresh five-year economic plan."

North Korea has shown off its nuclear and missile capabilities ahead of the party congress in an apparent bid to elicit strong allegiance from its people.

"North Korea will likely trumpet what it would call a success of the congress, but there is a low chance that tangible accomplishments will come out under the sanctions regime," said a source familiar with North Korean affairs.

North Korea has mobilized ordinary citizens to prepare for the congress under the "70-day campaign of loyalty" and forced them to offer money to authorities, inviting growing discontent from its people, according to a government official here.

"There is no indication that massive events for the congress are in the offing," he said, adding that Pyongyang's preparation for the convention appears to be lackluster.

There is a high possibility that the North will hold the party congress without high-profile foreign guests as more countries are believed to plan to shun it amid toughened international pressure, a Seoul official added.

A total of 177 delegates from 118 countries, including China and Russia, attended the party congress in 1980, according to Seoul's unification ministry. At the fifth congress in 1970, there were no foreign guests. (Yonhap)