SEOUL, South Korea (AFP) — The defense ministers of South Korea and Japan reaffirmed on Sunday their countries' commitment to the denuclearization of the Korean Peninsula, despite Pyongyang's repeated pledges to expand its nuclear arsenal.

The meeting comes after North Korean leader Kim Jong Un vowed to strengthen his country's defense capabilities, including equipping its navy with nuclear weapons and pressing ahead with missiles testing.

South Korean Defense Minister Ahn Gyu-back held talks with Japanese counterpart Shinjiro Koizumi in Seoul, who is on a two-day visit, during which the two agreed to explore ways to deepen defence cooperation.

Seoul and Tokyo are both security allies of Washington, but cooperation between their militaries has been hampered by historical tensions stemming from Japan's colonial rule of the Korean Peninsula in the early 20th century.

But the two "reaffirmed their commitment to the complete denuclearization of the Korean Peninsula and the establishment of lasting peace, and agreed to continue bilateral cooperation... as well as trilateral cooperation among South Korea, Japan and the United States," Seoul's defense ministry said in a statement released after the bilateral meeting.

The meeting also came weeks after the two neighbors held their first joint maritime search-and-rescue exercise in nine years, a move widely seen as another step towards closer defense cooperation.

The renewed commitment by the two defense chiefs to rid the peninsula of nuclear weapons, however, comes as Pyongyang has recently vowed not only to retain its nuclear arsenal but also to expand it.

The North Korean leader vowed earlier this month to beef up North Korea's defense capabilities, citing military modernization efforts by South Korea and the US that he said were pushing the region "to the brink of a nuclear war."

He also vowed that his country would equip its navy with nuclear weapons and build larger warships.

Pyongyang has repeatedly declared itself an "irreversible" nuclear state since a 2019 summit between Kim and his US counterpart Donald Trump in Hanoi collapsed over the scope of denuclearization and sanctions relief.

North Korea remains technically at war with the South because the Korean War ended in an armistice rather than a peace treaty.