North Korea's leader Kim Jong-un has reaffirmed his intent to stick to nuclear weapons when making his first military-related public activity since the party congress in May, the North's state media showed Monday.

Kim conducted the so-called field guidance at National Defense University, which the communist country says contributes to its defense industry, according to the North's official Korean Central News Agency. It did not specify the date of his visit.

Kim was quoted as saying by the KCNA that the mission of the university is to nurture talented people in a bid to further consolidate the country's status as a nuclear power state in the East.

It marked the first inspection into the defense sector since the country concluded the congress by the Workers' Party of Korea on May 9.

Since the party event, the North's young leader has focused on economy-related public activities including visits to a tree nursery and saltern, as he has stressed the need to boost its fragile economy on the principle of self-reliance.

At the party congress, Kim called his country a "responsible" nuclear state, saying that he will "permanently" defend the pursuit of his signature policy of developing nuclear weapons and boosting the country's moribund economy.

The KCNA said that the National Defense College, the predecessor of the university, was set up in October 1964 during the regime of the country's founder Kim Il-sung. (Yonhap)