A Republic of Korea Army soldier stands on a K21 tank on display at the Seoul International Aerospace and Defense Exhibition (ADEX) in Seongnam, south of Seoul, on Oct 18, 2021. (ANTHONY WALLACE / AFP)

SEONGNAM - The Republic of Korea should redouble its efforts to become a global defense industry leader, President Moon Jae-in told a military expo in the outskirts of Seoul on Wednesday, after landing at the site in an air force fighter jet.

Clad in a flight suit, Moon arrived at the biennial Seoul International Aerospace & Defense Exhibition in the back seat of an FA-50 jet fighter, the ROK's first indigenous supersonic aircraft and a major defense export.

The military display came a day after the Democratic People's Republic of Korea test fired a ballistic missile from a submarine. Last week the DPRK opened a defense exhibition of its own, where leader Kim Jong-un said his country's military developments were for self-defense and accused the ROK of destabilizing the peninsula with an arms build up.

The Republic of Korea plans to spend more than 80 percent of its acquisition budget on domestic supplies and to quadruple support for parts localization by 2026, with a focus on areas that could shape future wars, including AI, drones, robotics and space, the ROK's President Moon Jae-in said

In his speech on Wednesday, Moon defended ROK's increasingly sophisticated military as necessary for peace.

"The goal of building strong defense power is always to foster peace," he said.

Amid glittering displays of drones, sniper rifles, helicopters, missiles, and other weapons, crowds of company representatives, diplomats, and the ROK’s troops mixed with military delegations in an array of foreign uniforms.

At least 440 companies from 28 countries are participating in what organizers said was the largest ADEX ever. About 300 government, military and defense acquisition officials from 45 countries were expected to attend the event, which lasts through Saturday.

Moon said it was time for the ROK's arms industry to become a global leader.

Pointing the FA-50, he praised the ROK’s technology.

"I could feel the dashing dignity of the FA-50, which we've developed with our own technologies," Moon said.

READ MORE: DPRK leader: US, ROK threaten peace with military buildup

The ROK plans to spend more than 80 percent of its acquisition budget on domestic supplies and to quadruple support for parts localization by 2026, with a focus on areas that could shape future wars, including AI, drones, robotics and space, he said.

"We envision a smart yet strong military based on advanced science and technology, and promote peace together with the international community," Moon added.

The ROK's arms exports from 2016 to 2020 were 210 percent higher than from 2011 to 2015, according to Stockholm International Peace Research Institute data. It is also one of the largest arms importers in the world, buying major weapons systems such as American-made F-35 stealth fighter jets in recent years.