South Korean President Lee Myung-Bak rebuked his cabinet Monday for mishandling the signing of a landmark military pact with former colonial power Japan, but said his country still needs it.

The information-sharing pact, scheduled to be signed last Friday in Tokyo, would have been the first military agreement between Seoul and Tokyo since the end of Japan's brutal 1910-45 rule.

But Seoul postponed the signing at the last minute, amid growing criticism of the agreement itself and of the fact that it was pushed through secretively and without public or parliamentary consultation.

Many older Koreans have bitter memories of Japan's rule and military cooperation is a sensitive issue.

The government "did not submit a single report to the National Assembly (parliament) while entering into an agreement with a country that invaded us", said Lee Hae-Chan, chairman of the main opposition party.

President Lee admitted that there was "a procedural mistake" in the handling of the agreement.

"This was a matter that should not be handled without collecting public views sufficiently," the president was quoted by his spokesman as saying.

But it is still "is in our national interest", he said, instructing the cabinet fully to explain its contents to the public to avoid misunderstanding.

It was the second time Seoul had postponed the pact, which would have enabled Seoul and Tokyo to swap intelligence about North Korea's missile and nuclear programmes and other defence issues.

On Monday Foreign Minister Kim Sung-Hwan apologised and vowed to consult legislators before it is signed.

The planned pact had sparked angry reaction from opposition parties and activists in South Korea.

Historical disputes still mar the two countries' relationship despite their close economic relations.

They wrangle over ownership of rocky islets in the Sea of Japan (East Sea), and Tokyo has rejected talks on compensating Korean women used by Japan as military sex slaves during World War II.