Japanese Minister of Defence Takeshi Iwaya said on Friday South Korea's decision to end an intelligence-sharing pact was regrettable and showed it failed to appreciate the growing national security threat posed by North Korean missiles.
"North Korea's repeated missile tests threaten national security and cooperating between Japan and South Korea and with the U.S. is crucial," Iwaya told reporters. "We strongly urge them to make a wise decision."
South Korea said on Thursday it was ending the intelligence-sharing agreement with Japan, further straining ties between Seoul and Tokyo amid a dispute over South Koreans pressed into forced labour during Japan's wartime occupation of Korea.
Ties between the East Asian neighbors were already at their lowest ebb in years before Seoul's decision to end the General Security of Military Information Agreement (GSOMIA).
The dispute has spilled over into trade, with Japan putting restrictions on exports of semiconductor materials to South Korea and removing it from a list of nations given preferential trading terms.
Under the GSOMIA, which had been due for automatic renewal on Saturday, the two countries shared information on the threat posed by North Korea's missile and nuclear programs.
Scrapping the pact means Japan and South Korea may have to revert to sharing intelligence through the U.S. military.