SEOUL, Sept. 19 (Yonhap) -- Kim Jong-un, the third son of North Korean leader Kim Jong-il and his heir apparent, has been actively participating in the communist regime's politics and policymaking process, the defense ministry here said Monday.

Addressing North Korean affairs during the annual parliamentary audit, the ministry said North Korea has been laying down groundwork to "solidify its third-generation hereditary succession."

"Kim Jong-un has consistently involved himself in politics and policymaking," the ministry's report claimed. "On Sept. 9 this year, Kim appeared at the celebration of the 63rd anniversary of North Korea, a move that justified the third-generation hereditary succession."

In a similar report on the North's power succession, Seoul's Unification Ministry said that the younger Kim appears to have gotten a grip on power to some degree.

Kim has been involving himself in the North's economic and inter-Korean policies already with his men in the regime's internal power structure, including the military and public security organizations, the ministry said in the report submitted to a ruling party lawmaker.

Kim was named a vice chairman of the Central Military Commission of the North's ruling Workers' Party and a four-star general last year, in the clearest sign yet that he is poised to be the next leader.

Kim Jong-il inherited power from his father, the country's founder Kim Il-sung, who died in 1994.

"Kim Jong-un is expected to take similar steps as his father based on the premise that the power succession will go smoothly," the ministry said.

It forecast that the heir apparent is likely to assume such posts as a member or standing member of the party's politbureau, a secretary of the party's secretariat and a member of the powerful National Defense Commission, chaired by the current leader, in the future.

On the military front, the ministry said North Korea has been carrying out its annual summer drills since July.

"With the crab fishing season underway in the Yellow Sea, we're trying to control North Korean fishing boats around the Northern Limit Line and ratcheting up security there," the ministry said, referring to the de facto maritime border that the North refuses to recognize.

The volatile waters off the west coast have seen a series of North Korean provocations and bloody naval skirmishes.

The ministry noted that the North began its submarine infiltration drills in both the Yellow Sea and the East Sea earlier than usual, and it has retained its nuclear and long-range missile capabilities.

"Depending on changes to strategic situations, North Korea may possibly carry out provocations of varying forms," the ministry said.