MANILA – The Philippines and Vietnam reaffirmed that peace, stability, and freedom of navigation in the South China Sea are “non-negotiable,” as both countries moved to strengthen bilateral ties and renew a key defense cooperation agreement.

President Ferdinand R. Marcos Jr. made the statement following bilateral talks with visiting Vietnamese President To Lam, saying both sides—both claimant states in the disputed waters—share a firm position on maintaining stability in the strategic waterway.

“As fellow claimant states, we reaffirm that maintaining peace, stability, and the freedom of navigation and overflight in the South China Sea remains non-negotiable,” Marcos said.

During the visit, Manila and Hanoi renewed their 2010 defense cooperation agreement, which is expected to expand collaboration in maritime security, military education, and disaster risk reduction and management.

The South China Sea is a major global shipping route, with about one-third of global maritime trade passing through it annually. The Philippines, Vietnam, China, Malaysia, Brunei, and Taiwan maintain overlapping claims in parts of the resource-rich waters.

Both the Philippines and Vietnam have separately encountered maritime tensions with China over competing territorial claims in recent years.

Marcos said both countries remain committed to resolving disputes peacefully and in line with international law.

“We stand resolute in our commitment to the peaceful resolution of disputes, grounded firmly in international law, particularly the 1982 United Nations Convention on the Law of the Sea (UNCLOS) and the 2016 South China Sea Arbitral Award,” he said.

The 2016 ruling invalidated China’s expansive “nine-dash line” claim and affirmed the Philippines’ maritime entitlements under UNCLOS, although Beijing has rejected the decision. Vietnam was not part of the arbitration but has consistently upheld UNCLOS in its own maritime position.

Aside from defense cooperation, Marcos and Lam also discussed strengthening coordination against transnational crimes such as online fraud, human trafficking, illegal gambling, and people smuggling through enhanced intelligence-sharing and law enforcement cooperation.

The upgraded partnership comes ahead of the 50th anniversary of diplomatic relations between the Philippines and Vietnam in 2026 and as the Philippines chairs the Association of Southeast Asian Nations (ASEAN).