United States Vice President Kamala Harris on Monday personally reaffirmed the American government's commitment to the defense of the Philippines during her bilateral meeting with President Bongbong Marcos in Malacañang.

"We must reiterate always that we stand with you in defense of international rules and norms as it relates to the South China Sea, and armed attack on the Philippines, armed forces, public vessels, or aircraft in the South China Sea would invoke US Mutual Defense commitments," Harris told Marcos.

"The basis of our relationship is multifaceted. Our relationship is based on a mutual commitment to the economic prosperity of the region and our respective nations," she pointed out.

For his part, Marcos said in response: "I thank you for the very strong commitment that you have just made for the US to be defensive of the Philippines."

Harris arrived in Manila on Sunday, the first visit in five years by a high-ranking US official since former President Donald Trump visited the country in 2017.

Her three-day trip to the Philippines includes a stop in Palawan on the edge of the South China Sea, where she is expected to board a Philippine coast guard vessel.