MANILA - Former President Fidel V. Ramos on Tuesday praised Defense Secretary Delfin Lorenzana for leading a visit to Pag-asa Island in the disputed waters of the South China Sea.

"Let us commend Delfin Lorenzana, our Secretary of National Defense, for that very bold move. I’ve said it already in writing...and also the same for the civil staff of the Armed Forces," said Ramos in an interview with ANC's Headstart.

Last week, a Chinese station on Subi Reef in the disputed Spratlys challenged four times two Philippine fighter planes, one of which was carrying Lorenzana to Pag-asa Island.

• READ: China challenges PH planes en route to Pag-asa Island

Lorenzana said the pilots were warned the aircraft was illegally entering Chinese territory, a routine for all Philippine aircraft landing on the Thitu airstrip since China reclaimed Subi. He said his pilots disregarded the warning.

Beijing's Foreign Ministry Spokesperson Lu Kang said China is "gravely concerned" and "dissatisfied" with Lorenzana's visit, but Malacañang maintained that it was "lawful."

• READ: Pag-asa Island visit shows stronger PH position on sea disputes

Ramos said the Chinese may have been unaware that the Philippine defense chief was aboard the plane. He noted the challenge was made against an aircraft flying over Philippine territory nonetheless.

Ramos, who previously served as a special envoy to China in the Duterte administration's bid to amend ties with Beijing, said the matter should be brought up especially as Manila holds bilateral talks with China in May and hosts the ASEAN summit this year.

He said the Philippines should tell China: "This is ours and we are just conducting routine inspection of our facility. Do not resent it because we will not resent anything if your own facilities and we happened to be in the same vicinity. We will not protest."

"I think it is well known where the Philippine defenses are. Pag-asa is part of our Kalayaan municipality, already established since President Marcos’ time," added Ramos.

Pag-asa island is part of the Spratly archipelago just off the coast of Palawan.

Lorenzana flew to the island to check on its facilities, some of which were in dire need of repair. He vowed to upgrade Manila's facilities in the island after seeing how these paled in comparison with those built by China on its artificial islands.