The top security advisers of the Philippines and United States held their first official phone conversation over the weekend to discuss ways to further enhance the strategic partnership between the two nations, the National Security Council (NSC) disclosed Saturday, April 12.

During their introductory call last Friday, National Security Adviser Eduardo Año and US National Security Advisor Mike Waltz exchanged views on the regional security challenges, particularly in the South China Sea, as well as the West Philippine Sea (WPS), which continues to be central in Southeast Asian regional affairs amid growing maritime tensions.

They talked about future bilateral activities to “further accelerate the progress in the alliance,” the NSC noted.

Recognizing the importance of strength in numbers, Año and Waltz agreed that they have to engage with other “like-minded partners” to ensure a “free, open, and prosperous Indo-Pacific.”

“NSA Año and NSA Waltz agreed to continue their discussion to include close coordination at the working level,” the NSC mentioned.

Año then thanked Waltz for his continued assurance of the US’ ironclad commitment to the Philippines.

The US and Philippines have a long-standing treaty alliance as the two are bound by the Mutual Defense Treaty (MDT), a 1951 agreement that requires both countries to defend each other in case of an armed attack from a third-party.

Both countries have expressed strong opposition to China’s expansionist claims in the South China Sea, including in features located within the 200-nautical mile exclusive economic zone of the Philippines.