Practice Relating to Nuclear Weapons
The Philippines’ Republic Act No. 8438 (1997) provides: “It is the policy of the Cordillera Autonomous Region to prohibit the development, storage, use or transport of nuclear, biological or chemical weapons within the region.” 
Philippines, Republic Act No. 8438, 1997, Section 19.
In 1996, during a debate in the First Committee of the UN General Assembly, the representative of the Philippines stated:
In my region, where cold war tensions once reigned supreme, we have established a nuclear-weapon-free zone. There was a time when this would not have been possible. In 1991, the Philippine Senate rejected the agreement that would have allowed the biggest overseas United States military facilities to continue to remain in our country. In so doing, we removed the final obstacle for negotiations to begin in the Association of South-East Asian Nations (ASEAN) for a South-East Asia nuclear-weapon-free zone. Four years later, the gathered heads of the ASEAN nations and their counterparts from the rest of South-East Asia signed in Bangkok a Treaty that announced to the world the determination of the countries of South-East Asia to be free from nuclear weapons. 
Philippines, Statement before the First Committee of the UN General Assembly, UN Doc. A/C.1/51/PV.11, 22 October 1996, pp. 8-9.