STORY: Beijing claims almost all the South China Sea, which is believed to contain massive oil and gas deposits and through which billions of dollars in trade passes each year.
“We will continue to rally our allies and partners against unlawful and irresponsible behavior, when the international rules-based order is threatened somewhere, it is threatened everywhere. " Harris said while giving a speech aboard a Philippine Coast Guard vessel.
A 2016 ruling by an arbitration tribunal in the Hague said Beijing's South China Sea claims had no legal basis, delivering a victory for Manila. The Philippines has been unable to enforce the ruling and has since filed hundreds of protests over what it calls encroachment and harassment by China's coastguard and its vast fishing fleet.
Palawan is only about 200 miles from the Spratly islands, where China has dredged the sea floor to build harbors and airstrips. Parts of the archipelago are also claimed by Brunei, Malaysia, the Philippines, Taiwan and Vietnam.