North Korea said Monday it has adopted a decision by the ruling party's central committee to simultaneously pursue nuclear and economic development, and to reaffirm its leader's complete control.

The North's state media said the decision was unanimously adopted by party delegates on Sunday after North Korean leader Kim Jong-un reported works by the Workers' Party of Korea (WPK) at the party congress, a venue aimed at bolstering his monolithic power.

"We will consistently take hold on the strategic line of simultaneously pushing forward the economic construction and the building of nuclear force and boost self-defensive nuclear force both in quality and quantity, as long as the imperialists persist in their nuclear threat and arbitrary practices," the Korean Central News Agency (KCNA) said.

At the party gathering, the North's leader made it clear that he will "permanently" defend the pursuit of his signature policy of developing nuclear weapons in tandem with boosting the country's moribund economy, commonly known as the "byeongjin" policy.

He also called his country a "responsible nuclear weapons state," adding that Pyongyang will not use its nuclear arms first unless its sovereignty is threatened by other countries with nuclear bombs.

The KCNA said that party delegates have decided to hold the North's leader "in high esteem at the top post."

The seventh party congress, which kicked off Friday, is the first of its kind since October 1980 and also the first under the current leader, who assumed power in late 2011 following the sudden death of his father Kim Jong-il.

It is not known when the party gathering will end, but discussions of agenda items, including a revision of the party's rules, and the election of new party leadership will take place during remaining sessions. (Yonhap)