South Korea, the United States and Japan have signed a military pact on sharing sensitive information on North Korea’s nuclear and missile programs amid the communist country’s growing security threats to the region, Seoul’s defense ministry said Monday.

The pact went into effect Monday after a memorandum of understanding signed last week by South Korean Vice Defense Minister Baek Seung-joo and his counterparts Robert Work and Masanori Nishi was delivered to the U.S. side earlier in the day, the ministry said.

The trilateral arrangement allows Seoul and Tokyo to share military secrets on North Korea’s nuclear and missile threats via the U.S., which has bilateral military intelligence sharing accords with each of the two Asian countries.

It is the first trilateral agreement that opens the door for the three military partners to pool their intelligence on security threats from the communist country.

A copy of the agreement, provided by the ministry, shows that the information can be exchanged in any form, including documents, verbal communication, and visual and electronic materials.

South Korea and Japan, however, do not directly share sensitive information under the pact, an arrangement that reflects the bitter memory of Japan’s colonial rule of the Korean Peninsula from 1910-45.

When the South Korean and Japanese defense ministries intend to share secret information between them, they can do so by providing the information to the U.S. based on the accords, according to the agreement.

The latest pact is binding only diplomatically, not legally.

Seoul’s previous efforts to sign the agreement with Japan two years ago fell apart due to a public backlash.

The South Korean government plans to deliver second- and third-rate military secrets to Japan under the agreement.

The three countries plan to hold further discussions down the road to fine-tune the scope of intelligence sharing to be allowed under the pact, a defense ministry official said.

“Going forward, (the three countries) plan to have follow-up consultations to determine the level of information to be shared,” the official said. “The discussions will be about what kind of information will be provided under what circumstances, as well as what level of information will be passed when it is given off-line.”

In Washington, the U.S. Department of Defense said the MOU would advance the security of the three countries.

“In particular, information sharing among the signatories on the nuclear and missile threats posed by North Korea will allow for a more effective response to future provocations and during contingencies,” the Pentagon said in a statement.

The arrangement creates a framework by which the defense authorities of the three countries may voluntarily share classified information, the statement said. It added that the U.S. will serve as the “hub for information shared trilaterally” and the arrangement does not impose any new legal obligations on the signatories.

The latest military arrangement among the three military partners came after the North has repeatedly threatened to conduct another nuclear test, with the latest threat coming over the United Nations’ resolution on the country’s human rights violations.

Pyongyang has carried out three underground nuclear detonations since 2006, with the outside world suspecting that the country is close to completing the development of an inter-continental ballistic missile.

Monday’s announcement of the signing, however, is expected to spark political controversy and public opposition, with lawmakers criticizing the advance signing of the agreement without notifying the parliament.

“The U.S. signed the info-sharing pact on Dec. 23 while Japan and our country did it on Dec. 26,” Defense Minister Han Min-koo told lawmakers. “(The countries) set the date of (the deal taking effect) on Monday due to the time needed for procedures,” Han said.

The parliament was notified of the signing of the agreement hours after it went into effect.

Han indicated that the latest deal, which is not binding under international law, does not require ratification from the National Assembly.

“Although the agreement was signed in the form of a pact at the level of (defense ministry) institutions, (not countries), it requires ratification because it directly concerns national security,” said Jin Sung-Joon, a lawmaker of the main opposition New Politics Alliance for Democracy.

A week ago, dozens of South Korean civic groups held a joint news conference in front of the defense ministry’s building, slamming Seoul’s push to share military information with Tokyo.

The groups expressed concern that the pact may lead South Korea to join the U.S.-led missile defense system, heightening tensions in Northeast Asia. (Yonhap)