MANILA - Chinese President Xi Jinping broke a 2015 promise not to militarize its artificial islands in the South China Sea, Acting Supreme Court Chief Justice Antonio Carpio said on Sunday.

Carpio made this statement following reports that China installed missiles on the islands it reclaimed in the Spratlys.

In 2015, Reuters reported that Chinese President Xi Jinping during a meeting with then US President Barack Obama, denied that China was militarizing the islands.

"China has just broken that promise by installing long-range anti-ship cruise and anti-aircraft missiles on these artificial islands," Carpio said.

"Filipinos must judge China by its actions, not by its promises of friendship to the Philippines," he added.

US network CNBC reported earlier that the Chinese army had installed anti-ship and air-to-air defenses on outposts also claimed by Vietnam and the Philippines over the last 30 days, citing sources close to the US intelligence.

Carpio explained that an international arbitration court had already ruled that Subi Reef is part of the territorial sea of Pagasa Island, which is occupied by the Philippines, and the Mischief Reef as part of the country's the exclusive economic zone.

The Acting Chief Justice urged the Duterte administration to protest China's installation of missiles saying this was necessary to preserve the Philippines' sovereignty over the disputed waters.

"At the very least the Philippine Government must officially protest China's installation of missiles on these artificial islands. This is necessary to preserve the sovereignty and sovereign rights of the Philippines over these areas," he said.

The Chinese foreign ministry has neither confirmed nor denied the deployment.

• Beijing 'installs missiles' on South China Sea islands

In a statement Sunday, Senate President Aquilino "Koko" Pimentel said the Senate Foreign Relations Committee shall verify China's reported militarization of the disputed islands.

If confirmed, Pimentel said they will have a closed-door confidential briefing on how the Department of Foreign Affairs will handle the issue.

BASAHIN: Senate President Koko Pimentel, ipinababatid sa Senate Foreign Relations Committee kung totoo ang balitang naglagay ng missile sa West Philippine Sea ang China; closed-door meeting kasama ang DFA, nakatakda sa pagbabalik ng sesyon | via @ZandroDZMM pic.twitter.com/nlLcnWudVr

— ABS-CBN News (@ABSCBNNews) May 6, 2018

President Rodrigo Duterte has not called out China over the reported missile deployment but instead blamed the United States and former President Benigno Aquino III for their supposed failure to stop China’s militarization of the disputed seas.

• Duterte hits US, Aquino amid Chinese ‘militarization’ in S. China Sea