Marcos made the remarks in a speech to the Shangri-La Dialogue in Singapore, attended by defence ministers from around the world, including the United States and China.

The Philippines, a treaty ally of the United States, is a key focus of Washington's efforts to strengthen alliances and partnerships in the Asia-Pacific region as it seeks to counter China's growing military might and influence.

Given its position in the South China Sea and proximity to self-ruled Taiwan, which China claims as its own, Philippine support would be crucial for the United States in the event of any conflict.

The Philippines expanded a 2014 agreement last year to give US military access to another four if its military bases, taking the total number to nine, including two in the far north of the country, less than 450 kilometres (280 miles) from Taiwan.

The Enhanced Defence Cooperation Agreement (EDCA) allows US troops to rotate through and store defence equipment and supplies, and has infuriated Beijing.