The Philippine government is taking "appropriate diplomatic action" to protect its claims in the South China Sea but did not elaborate or name China in a non-confrontational policy to avoid problems.

China reportedly landed long-range bombers on one of its occupied islands for the first time in its latest military action in the disputed seas, setting off international concern. A Pentagon spokesman said late last week China's "militarization" of disputed areas destabilizes the region.

The Philippine Department of Foreign Affairs reiterated Monday the government is committed to protecting "every single inch" of its territory and areas where it has sovereign rights. But it added that its responses to certain developments might not be publicized.

"While appropriate language, whether expressions of condemnation or concern, over certain developments are clearly conveyed through diplomatic channels, it is not our policy to publicize every action taken by the Philippine government whenever there are reported developments taking place," the department said.

"Moving forward, we are taking a different approach to avoid any drawbacks and challenges," the statement added.

After rising to power nearly two years ago, President Rodrigo Duterte took steps to thaw the Philippines' frosty ties with China over the sea disputes in an effort to secure Chinese infrastructure funds and investment while often criticizing security policies of the United States, his country's treaty ally.

Duterte refused to immediately demand Chinese compliance to a landmark 2016 arbitration ruling that invalidated China's claims to virtually all of the South China Sea on historical grounds and upheld the Philippines' sovereign rights to vast stretches of waters.

The Duterte administration has also muted criticisms of China's increasingly assertive actions in the disputed territories, including the installation of missile defense systems on seven islands it built on disputed reefs close to other areas occupied by rival claimants, including the Philippines, Vietnam, Taiwan and Malaysia.

The long-range bombers involved in the recently reported exercise would have all of Southeast Asia in range. They reportedly landed on Woody Island, China's largest base in the Paracel Islands that are also claimed by Vietnam and Taiwan.

The Department of Foreign Affairs said the Philippines had gained much under Duterte and intended to achieve more.

Critics and nationalists have accused Duterte of squandering the Philippines' arbitration victory and helping embolden China.

Renato Reyes of the left-wing group Bayan called the Duterte administration's approach to the territorial disputes "defeatist.

"Asserting our sovereign rights does not mean we intend to go to war with China and end up losing," Reyes said. "It simply means we are telling China and the entire world that we have sovereign rights in those waters under international law. It means we have not surrendered those rights."