North Korea on Wednesday trumpeted the accomplishments of its leader Kim Jong-un ahead of the key party congress slated for later this week, stressing that the country has legitimacy in possessing nuclear weapons.

The Rodong Sinmun, the North's main newspaper, described the North's leader as "the great sun of the 21st century," listing a set of Kim's feats including what it calls successful launches of ballistic missiles from a submarine.

It said the North's leader has achieved a litany of successes like building up a thriving country, but in that process, North Korea has to tackle challenges from its enemies including the U.N. sanctions and joint military drills between Seoul and Washington.

The paper said in its commentary that a nuclear weapon is a "precious sword" with which the North can counter what it calls Washington's nuclear threats.

The message came as the Workers' Party of Korea plans to hold its first party congress in 36 years on Friday, a move expected to help the North's leader take a firmer grip on power.

The party congress is likely 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 appears to seek to establish the socialist party-centered system and further consolidate the Kim Jong-un regime through the upcoming party congress," Jeong Joon-hee, a spokesman at Seoul's unification ministry, told a regular press briefing.

In March, the North's leader said that his country is ready to conduct a nuclear warhead test and launch ballistic missiles "in a short time," in apparent defiance of tougher international sanctions.

"We think that North Korea can carry out a nuclear test at any time," Jeong said. "We are closely monitoring the situation and are raising our guard against (the North's possible provocation)." (Yonhap)