US Vice President Kamala Harris and Philippines President Ferdinand Marcos. (Photo: AP)

Harris stressed the importance of the two countries’ relationship in finance and security and welcomed extended cooperation with the Philippines for a free and open Indo-Pacific region.

She said an attack on the Philippines’ armed forces, public vessels, or aircraft in the Pacific would invoke Article 4 of the 1951 Mutual Defense Treaty, which guarantees the US’s protection of Philippine territory in the Pacific.