A Pentagon spokesperson on Tuesday cast the current level of trilateral security cooperation between South Korea, the United States and Japan as "unprecedented," as concerns have arisen over North Korea's continued missile launches and tough rhetoric.

The spokesperson made the remarks after Japan's Yomiuri Shimbun reported recently that the three countries shared radar information for the first time when the North fired a ballistic missile on Jan. 14, and that despite three-way efforts, Japan's Self-Defense Forces' radar appears to have been unable to track it through its terminal phase.

In December, Seoul, Washington and Tokyo began operationalizing a mechanism for the real-time sharing of North Korean missile warning data in line with their leaders' summit agreement in August.

"As we said in December, we have fully activated a real-time DPRK missile warning data sharing mechanism. These achievements and other ongoing efforts demonstrate the unprecedented depth, scale and scope of trilateral security cooperation by the US, the Republic of Korea, and Japan," the spokesperson told Yonhap News Agency via email.

DPRK refers to the North's official name, the Democratic People's Republic of Korea.

"We do not intend to publicly share detailed analysis on each launch, but we will continue working with our allies about how to best engage the DPRK, deter aggression, and coordinate international responses to the DPRK's ongoing and dangerous provocations," the official added.

The launch of the data sharing mechanism was a culmination of trilateral security cooperation in the face of evolving North Korean nuclear and missile threats and other security challenges.

Since the beginning of this year, Pyongyang has engaged in a series of weapons tests, including the test-firing of strategic cruise missiles -- a development that underscored the need for deeper cooperation between the US and its two core Asian allies. (Yonhap)