South Korea said Friday it will share military intelligence with Japan through the United States after terminating a pact that enabled the two key Washington allies to exchange such information directly.

Seoul's decision on Thursday to end the General Security of Military Information Agreement (GSOMIA) was the latest in a series of tit-for-tat measures that have brought relations between South Korea and Japan to their lowest point in years.

The intensifying trade and diplomatic dispute was sparked by a run of South Korean court rulings against Japanese firms, requiring them to pay for forced labour during World War II — a long-standing point of contention.

Under the GSOMIA, originally signed in 2016, the two had directly shared military secrets, particularly over North Korea's nuclear and missile capacity.

But now South Korea will "actively utilise the trilateral information-sharing channel with the United States as the intermediary" in place of the accord, said Kim Hyun-chong, a national security official at the presidential Blue House.

"Furthermore, the ROK government will actively enhance our defence capabilities through the increase in (the) defence budget and the acquisition of strategic assets including military satellites" to better monitor North Korea, he added, using the initials of South Korea's official name.

It came after US Secretary of State Mike Pompeo said on Thursday that Washington was "disappointed" about South Korea's move to end the pact.

Both Japan and South Korea are market economies and major US allies faced with an overbearing China and nuclear-armed North Korea.

But their relationship continues to be heavily affected by Japan's 35-year colonial rule of the Koran peninsula in the early 20th century.

Japan says a 1965 treaty that normalised relations with a significant financial contribution effectively settled all reparation claims.

Japan 'strongly' protests South Korea defence pact move: FM
Tokyo (AFP) Aug 22, 2019 –

Japan's foreign minister said Thursday that Tokyo "strongly" protested against South Korea's decision to scrap a military intelligence-sharing pact, calling the move "extremely regrettable".

"I have to say the decision to end the pact by the South Korean government is a complete misjudgement of the current regional security environment and it is extremely regrettable," Taro Kono said in a statement.

"We cannot accept the claims by the South Korean side and we will strongly protest against the South Korean government," Kono said, adding that Tokyo had summoned the South Korean ambassador.

Earlier, Seoul had announced it was "not in the national interest to maintain the agreement that was signed for the purpose of exchanging sensitive military intelligence".

The end of the General Security of Military Information Agreement (GSOMIA) marks a fresh low point in relations between the two democracies and US allies and is likely to be seen with dismay in Washington.

It was the latest in a series of tit-for-tat measures that began with a run of South Korean court rulings against Japanese firms, requiring them to pay for forced labour during World War II.

The diplomatic spat has bled through into the trading relationship between the two high-tech economies, with both removing each other from a list of trusted trading partners.

Seoul's surprise move came just one day after Kono met his South Korean and Chinese counterparts in Beijing and the trio pledged to diffuse regional tensions, with one eye on North Korea's belligerence and nuclear threat.

Kono insisted that scrapping the pact and Japan's decision on the trade restrictions were completely different issues.