MANILA – The United States reaffirmed on Wednesday its “ironclad commitment” to its alliance with the Philippines as the two countries mark 72 years since the signing of the Mutual Defense Treaty.

The MDT, signed in 1951, obligates both sides to come to each other’s defense in case an external party attacks the Philippines or the US.

“The United States stands firm in our ironclad commitment to our alliance and partnership with the Philippines as we face new and continuing challenges,” US Ambassador MaryKay Carlson said over Twitter.

US Defense Secretary Lloyd Austin III has previously reiterated that an armed attack on Philippine armed forces, aircraft and public vessels, including the Coast Guard, anywhere in the South China Sea, would invoke Washington DC’s mutual defense commitments under Article IV of the MDT.

The US Embassy in Manila emphasized that the pact continues to serve as the foundation for the Philippine-US’ “evolving alliance” and that both sides’ security forces would continue to strengthen their capabilities and work together to secure a “free and open Indo-Pacific.”

The two states earlier announced plans to expand new military sites in the Philippines under the Enhanced Defense Cooperation Agreement, a 2014 agreement that seeks to advance the MDT’s implementation.

The four new sites — Naval Base Camilo Osias in Santa Ana, Cagayan; Camp Melchor Dela Cruz in Gamu, Isabela; Balabac Island in Palawan; and Lal-lo Airport in Cagayan – aim to strengthen the interoperability of the US and Philippine armed forces.

Pillar of PH security

Meanwhile, the Armed Forces of the Philippines said the 72-year-old MDT is a “pillar” of the country’s security.

“The MDT is one of the pillars of our national security. The mechanisms under it shall continue to be implemented to further enhance the capability of the AFP to perform its constitutional duty of protecting  our national sovereignty and territorial integrity,” military spokesperson Col. Medel Aguilar said in a statement Wednesday. (with Priam Nepomuceno/PNA)