The recently concluded Asia Security Summit included a statement by the defense chiefs of South Korea and Japan affirming their opposition to North Korea’s weapons proliferation programs.

However, one observer said Sunday that this should not be seen as a sign of warming ties.

South Korean Defense Minister Han Min-koo, his Japanese counterpart Gen Nakatani and U.S. Secretary of Defense Ashton Carter issued a joint statement underlining their “immutable opposition to North Korea’s possession and continued development of nuclear weapons and their means of delivery.”

They also highlighted their tripartite December intelligence-sharing agreement.

The Asia Security Summit, also known as