During the weekend, two U.S. warships sailed close to the Paracel Islands, north of the Spratlys, drawing protests from China. China this month deployed anti-ship cruise missiles and surface-to-air missiles on the disputed Spratly Islands off the Philippine coast and flew nuclear-capable bombers to a base in another disputed part of the sea.
REFUTING domestic criticism that of its soft stance on China's militarisation of the South China Sea, the Philippines said it was prepared to go to war with the country if any of its military personnel are harmed in the disputed waters.
"I challenge anyone of them, whatever their profession - justice, politician, newsman, journalist - if we lost a single island during Duterte's time, I will pack my bags, go home".
Yue Gang, a retired PLA colonel and military analyst, said the security dialogue had often provided a platform for the USA and its allies to raise their concerns about China.
"President Duterte's approach is prudent, patient and pragmatic".
China thought otherwise, calling the presence of the USA ships unauthorized and provocative.
China has also deployed YJ-12B anti-ship cruise missiles and HQ-9B surface-to-air missiles to islands in the Spratlys, boosting China's ability to combat US aviation and naval assets should such action be necessary.
Esperon reported that five lighthouses have been built on Pag-asa, Likas, Parola, Patag and Kota islands - all part of the Kalayaan Group of Islands "to ensure safety of navigation, along our responsibility under the UNCLOS (United Nations Convention on the Law of the Sea) to provide navigational safety for all global vessels transiting the West Philippine Sea".
"This administration does not and will not abandon the ruling of the Permanent Court of Arbitration on the South China Sea disputes".
Alan Peter Cayetano used the term "West Philippine Sea", to denote those waters that are within the country's 370-kilometre exclusive economic zone.
"The government is presently upgrading port and airstrip facilities in Pag-asa Island, in line with efforts to promote the welfare of Filipinos living in the said island", he said. "If there's multiple nation militarizing, and it isn't exclusively the islands, if big navies are crusing by means of the world, is that not militarization?" he mentioned.
Esperon made the remarks after some groups criticized the government for not doing enough to protest China's increased militarization in the South China Sea.
Mattis said US diplomats were engaged on the issue and he had heard concerns about Chinese actions not just from within the United States government, but also from regional allies.
China claims most of the resources-rich sea through which $5 trillion in shipping trade passes annually, and in recent years has reclaimed reefs and shoals including some claimed by Manila.
Manila is pursuing a joint exploration agreement with Beijing for oil and natural gas reserves in their claimed territory in the South China Sea.
Our diplomats are robustly engaged on this.
Mattis is stopping in Hawaii on his way to the Singapore meeting so that he can attend the ceremony marking the change in leadership at U.S. Pacific Command.
He told reporters on the flight that, despite the administration's focus on North Korea, other regional security issues, including the South China Sea, will be top priorities. He will be replaced by Admiral Philip Davidson.