The United States (US) is already planning an expansion of its missile defense in Asia, including the Philippines.
In a report from the Wall Street Journal, the buildup will supposedly be used to counter threats from North Korea and China.
The report said: "The expansion comes at a time when the U.S. and its allies in the region voice growing alarm about a North Korean missile threat. They are also increasingly worried about China's aggressive stance in disputed waters such the South China Sea, where Asian rivals are vying for control of oil and mineral rights."
The report quoted Congressional Research Service missile-defense expert Steven Hildreth, who said that the US is looking "longer term at the elephant in the room, which is China."
The report added that the expansion includes the deployment of an early-warning radar in the southern part of Japan.
The deployment of the so-called X-Band radar there is still being discussed, however. Earlier, both the allies already ruled out the deployment in Okinawa because of disapproval from residents.
As such, "Some U.S. defense officials have focused on the Philippines as the potential site for the third X-Band, which is manufactured by Raytheon Co. Pentagon officials said a location has yet to be determined and that discussions are at an early stage," the report added.
The Philippines have lodged several protests against China for its incursion in several disputed areas, including the Scarborough Shoal.
China earlier rebuked a senior diplomat of the US there after he raised concerns over the tensions in the disputed West Philippine Sea.
The US embassy's deputy chief of mission was even summoned to explain.