"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.