Malacanang on Friday said they remained ''steadfast'' in maintaining the country's claims with respect to territory and exclusive economic zones pursuant to law.

Presidential spokesperson Salvador Panelo made the statement after Chinese Foreign Ministry spokesperson Lu Kang said Thursday they have historical and legal basis in claiming the Nansha Islands and their fishermen rights should not be challenged.

Citing ''hard won positive momentum'' in ties between China and the Philippnes, Kang said: ''We hope that the Philippine side can join us in properly managing the South China Sea issue, upholding peace and tranquility on the sea, and bringing more benefits to the two peoples.''

"While we concur with the Chinese official's statement that the dispute can be best threshed out through peaceful negotiation and consultation between the two countries... the arbitral ruling however has already been rendered and we remain steadfast in maintaining our claims with respect to our territory and exclusive economic zones pursuant not only to the said arbitral judgment based on accepted principles of public international law but consistent with the directives of our Constitution and the aspirations of the Filipino people," said Panelo.

Panelo is referring to the 2016 ruling by an international court that nullified China's basis in claiming disputed areas in the South China Sea under its nine-dash line.

He said it is the country's principled stand that peace in the West Philippine Sea should be maintained and China should avoid performing acts that will place at risk the Filipino fishermen fishing in the disputed areas.

"And at the same time cause irritants that will disrupt the current friendly relations of the two countries as well as imperil future bilateral negotiations on matters of mutual concern," he said.

"As a matter of protocol, we expect our Philippine counterpart, the Department of Foreign Affairs, to issue an official statement on the matter," he added.

President Rodrigo Duterte earlier issued a strong statement against the presence of Chinese ships near Pag-asa Island, which is part of the Kalayaan municipality in Palawan.

He has said Pag-asa belongs to the Philippines and China should lay off the island. Ella Dionisio/DMS