South Korea, the U.S. and Japan will sign a trilateral information-sharing arrangement on Monday to better handle the evolving nuclear and missile threats from North Korea, Seoul’s Defense Ministry said Friday.

The arrangement is expected to strengthen the three-way security cooperation that has been lackluster due to historical and territorial feuds between Seoul and Tokyo, and Seoul’s push for a deepened strategic partnership with Beijing.

South Korea’s Vice Defense Minister Baek Seung-joo, U.S. Deputy Defense Secretary Robert Work and Japan’s Vice Defense Minister Masanori Nishi will sign the arrangement separately in their respective countries on Monday.

Under the deal, South Korea and Japan will not directly share their military information, but they will share it via the U.S. upon their consent, Seoul officials explained. Such an indirect method has been devised apparently in consideration of the public sentiment in the South against any military collaboration with its onetime colonizer.

“If South Korea offers information to the U.S., the U.S. would provide it to Japan upon South Korea’s consent. On the other hand, if Japan offers information to the U.S., the U.S. would give it to the South upon Japan’s consent,” a senior official at the Defense Ministry told reporters, declining to be named.

“The sharing will be limited to information about North Korea’s nuclear and missile threats. The country that has produced a particular piece of information will determine to what extent it will share its information.”

South Korea has been sharing intelligence with the U.S. under a 1987 information-protection pact, while Japan has been sharing information with the U.S. according to a 2007 information-protection pact.

The trilateral arrangement is based on these bilateral pacts that are binding under international law, and would guarantee the protection of any information shared among the three partners, Seoul officials said.

Seoul believes that the trilateral information sharing will enhance the “quality and credibility” of intelligence on North Korea’s military threats.

“Japan has six surveillance satellites, missile detection equipment on their Aegis ships and other intelligence assets that would help us better detect military movements in North Korea,” said the Seoul official.

“If we piece together all of our information, we will be able to more accurately analyze North Korea’s missile movements from all stages ― boost, cruising and terminal. We will also be able to better analyze how North Korea operates its missile force at a tactical level.”

The three countries agreed to discuss the trilateral information sharing in May when their defense chiefs met on the sidelines of the Shangri-La Dialogue, an annual security forum in Singapore.

Their discussion on the deal came after Pyongyang successfully fired a long-range rocket with an estimated range of 10,000 kilometers in December 2012, and conducted a third nuclear test in February 2013.

Pyongyang has a wide range of missiles that can strike South Korea, Japan and potentially the U.S. mainland.

Its Scud missiles with ranges of between 300 kilometers and 1,000 kilometers are largely targeted at South Korea, while Rodong missiles are aimed at Japan. It also has the Musudan missile with a range of more than 3,000 kilometers.

The North has also been developing intercontinental ballistic missiles such as the Taepodong-2 missile with a range of around 10,000 kilometers, and the KN-08 missile with an estimated range of 12,000 kilometers, which was unveiled in a military parade last year.

The trilateral information cooperation has sparked a controversy here, with some arguing that the deal will bring South Korea closer to its participation in the global U.S.-led missile defense program.

Seoul’s Defense Ministry said that the information sharing does not entail its participation in the U.S. MD program.

It reiterated that it would operate an independent low-tier missile defense program, and that it would only seek intelligence sharing with the U.S.

“The U.S. has its own MD program, and we have our own for which we will independently develop, plan and implement our operational procedures. It is not that we are joining the U.S. MD program,” the official said.

Seoul has been reluctant to join the U.S. MD system as it could cause diplomatic friction with China and Russia that believe the U.S. military program, despite its defensive nature, could potentially target them.

Civic groups have protested the decision over the information sharing, arguing that the deal was signed without seeking domestic public consensus, particularly at a time when Tokyo has failed to fully atone for its wartime atrocities.

By Song Sang-ho (sshluck@heraldcorp.com)