Adm. Scott Swift, who assumed command of the Pacific Fleet in May, said the Navy may deploy more than the four littoral combat ships it has committed to the region.
Swift also disclosed that he was "very interested" in expanding annual combat exercises the US Navy holds with each of several allies into a multi-nation drill, possibly including Japan.
Asked how many resources the US military was ready to devote to the South China Sea, Swift told a small group of journalists in Manila that he understood the concerns of America's allies.
"If we had the entire Unites States Navy here in the region, I think people would still be asking, 'Can you bring more?'"
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Long-running territorial disputes involving China, the Philippines, Vietnam, Taiwan, Malaysia and Brunei have flared on and off for years, sparking fears that the South China Sea could spark Asia's next major armed conflict.
Tensions flared again last year when China launched massive island-building in at least seven reefs it controls in an offshore region called the Spratlys.
The US, Swift stressed, doesn't take sides but would press ahead with operations to ensure freedom of navigation in disputed waters and elsewhere.
Swift cited the US military's massive response to help the Philippines following Typhoon Haiyan's devastation in 2013 as a demonstration of America's commitment to help a troubled ally.
It remains unclear what China intends to do with the artificial islands but Swift said it was clear those areas remain disputed and added they would not hinder US military operations in the disputed region.