HONOLULU -- President Ferdinand Marcos Jr. of the Philippines said the situation in the South China Sea "has become more dire" as China expands its presence in an area where multiple nations have competing territorial claims.
China has showed interest in atolls and shoals that are "closer and closer" to the coast of the Philippines, with the nearest atoll about 60 nautical miles away, Marcos said.
"Unfortunately, I cannot report that the situation is improving," Marcos said Sunday. "The situation has become more dire than it was before."
Marcos spoke during a question-and-answer session after he delivered a talk at the Daniel K. Inouye Asia-Pacific Center for Security Studies in Honolulu. The Philippines president stopped in Hawaii to meet with U.S. military leaders and the local Filipino community on his way home from a regional summit meeting in San Francisco.
His trip comes at a time when the United States and the Philippines have been deepening their longstanding alliance in a shift after Marcos' predecessor, Rodrigo Duterte, nurtured cozy ties with China and Russia.
China claims virtually the entire South China Sea as its own territory and refuses to acknowledge claims from the Philippines and four other governments to some or all of the waterway. Beijing has dismissed the findings of a U.N.-backed arbitration tribunal that invalidated China's sweeping historical claims under the U.N. Convention on the Law of the Sea.
"The Philippines will not give a single square inch of our territory to any foreign power," he said in his speech.
The U.S. says China has militarized several islands it built in the area, arming them with anti-ship and anti-aircraft missile systems, laser and jamming equipment and fighter jets.
Marcos said features in the South China Sea are "slowly being turned into bases." He said Adm. John Aquilino, the top U.S. military commander in the Indo-Pacific region, showed him a model of one earlier in the day.
The level of commitment China made "to those military bases" was "remarkable," Marcos said.
Tensions in the area have risen recently as China has blockaded an isolated Philippine marine outpost on Second Thomas Shoal, also known as Ayungin Shoal.
Last month, a Chinese coast guard ship and an accompanying vessel rammed a Philippine coast guard ship and a military-run supply boat near the contested shoal, according to Philippine officials. China accused the Philippine vessels of trespassing in what it said were Chinese waters "without authorization" despite repeated radio warnings.
The U.S. and the Philippines have a mutual defense treaty dating to 1951.
Marcos said the U.S., as its only treaty ally, was its main partner, but he said Manila also was seeking to strengthen ties with other nations sharing its ideals and values, noting the examples of Australia, Japan and South Korea.
He said the Philippines also was seeking to negotiate a code of conduct with Vietnam and Malaysia, other nations with whom it has territorial conflicts.
Marcos' remarks came after he met Friday with Chinese President Xi Jinping on the sidelines of the Asia Pacific Economic Cooperation summit.
He told reporters afterward that they agreed the challenges in the South China Sea "should not be the defining element" of their relationship. Marcos said the two leaders tried to come up with mechanisms to lower tensions in the South China Sea.