Seoul and Tokyo have formally signed an agreement which will enable the two sides to share their military intelligence on North Korea’s missiles and nuclear weapons.

South Korea's Defense Minister Han Min-koo and Japanese Ambassador to Seoul Yasumasa Nagamine signed the General Security of Military Information Agreement(GSOMIA) on Wednesday.

The deal took effect later on Wednesday after the two sides notified each other in writing that they have completed the proper domestic procedures on the deal.

The signing of the deal, following a tentative agreement early this month, came in less than a month’s time since the South Korean government’s announcement that the two sides will resume negotiations for it after a four-year halt due to fierce public opposition in South Korea.

It is the first military deal signed between the two countries since the Korean Peninsula’s liberation from Japan’s colonial rule in 1945. Prior to the deal, Seoul and Tokyo had shared military intelligence indirectly through the U.S. under a trilateral intelligence sharing deal signed in 2014.

In a statement signed by National Security Council(NSC) Spokesman Ned Price, Washington welcomed the GSOMIA deal between Seoul and Tokyo, saying it will allow Washington's two closest allies in the region to “significantly strengthen" bilateral, as well as three-way cooperation with the U.S., on deterring and defending against North Korea's threats.

The agreement stipulates general security principles regarding military intelligence sharing between countries, such as methods of sharing, protecting and destroying related intelligence. The intelligence to be exchanged is second- or lower-tier classified information. The deal will remain in effect for a year, and then will be automatically extended each year unless either side notifies otherwise.

Local military experts welcomed the agreement, saying it will create synergy between South Korea’s human network and Japan’s reconnaissance ability and boost Seoul’s ability to monitor North Korea.

However, criticism abounds in South Korea that the timing isn't ripe for such an agreement when Tokyo doesn't appear to be remorseful about atrocities committed by the Japanese military during World War II.

The three South Korean opposition parties agreed to propose a motion to dismiss Defense Minister Han over the signing of the GSOMIA.