The UN-backed tribunal on Tuesday ruled against China but Beijing rejected the decision, warning of a "decisive response" to provocative actions against its security interests based on the verdict.
Philippine President Rodrigo Duterte announced late Thursday he would send a former president, Fidel Ramos, to China to start talks on the ruling of The Hague-based Permanent Court of Arbitration.
Manila's top government lawyer, Jose Calida, stressed on Friday there would be no concessions to China.
"We value the award given by the (tribunal), and the Philippines will not concede any of the awards given to us," Calida said, using the legal term for the ruling.
The tribunal found there was no legal basis for China to claim historic rights to resources in areas falling within its nine-dash line, which is based on a vague map that emerged in the 1940s.
The nine-dash line overlaps with waters also claimed by the Philippines, Brunei, Malaysia, Taiwan and Vietnam.
The tribunal also ruled Beijing had violated the Philippines' sovereign rights to exploit resources in waters up to 340 kilometres beyond its coast, called its exclusive economic zone.
China had built artificial islands atop seven reefs in the area, inflicting severe environmental damage, the tribunal said.
"We will use diplomacy. I believe this is the most peaceful way of settling this," Calida said, adding Duterte had set no timeframe for achieving results.
"We will be patient of course and hopefully China will show the same grace that we have shown," Calida added.
Duterte, who took office on June 30, has said he wants better relations with China and to attract Chinese investment for major infrastructure projects.
Ramos, who served as president from 1992 to 1998, is also known to favour close ties with China. However he has yet to accept the mission.
Sino-Philippine relations plummeted over the maritime row under Duterte's predecessor Benigno Aquino, whose government filed the arbitration case in 2013.
Senior Supreme Court associate justice Antonio Carpio warned Friday it would be illegal for Manila to jointly develop with China or any other country the resources in the areas adjudicated as part of the Philippines' exclusive economic zone.
Carpio, a member of the Philippine team that brought the suit against China, told a public forum the Filipino constitution reserved the "use and enjoyment" of the resources in this vast maritime zone exclusively to Filipinos.
But he said Manila may engage foreign entities as contractors to extract or develop these resources.
In response, Calida said: "Certainly we will not do something illegal or unconstitutional".
