United States (US) Secretary of State Marco Rubio reaffirmed Washington's commitment to strengthening security and economic cooperation with Southeast Asia, saying the US will continue supporting the region's sovereignty, maritime security and long-term growth as it approaches 50 years of relations with the Association of Southeast Asian Nations (ASEAN) in 2027.

In an opinion piece published Tuesday, Rubio said the US considers a stable and prosperous Southeast Asia vital to its national interests, citing decades of economic engagement and security cooperation with ASEAN member states.

Rubio reiterated that the US remains committed to keeping vital sea lanes in the region free and open, stressing that freedom of navigation is essential to global trade and regional stability.

"This year marks the 10th anniversary of the 2016 Arbitral Tribunal ruling on the South China Sea, which is final and binding," Rubio said.

The secretary also said the US will continue to stand for lawful maritime rights and freedom of navigation in the region, honoring its obligations to the Philippines and other allies as they confront new and coercive threats to our shared interests.

Rubio also asserted that Washington is providing $100 million to help strengthen the Philippines' defense capabilities and support efforts to resist coercion in the region, highlighting expanding economic opportunities between the US and ASEAN.

He said Southeast Asia will be a key focus of President Donald Trump's American AI Exports Program, which seeks to accelerate digital transformation by providing partner countries with US artificial intelligence technologies.

On energy and infrastructure, Rubio said the US is supporting projects aimed at improving energy security and regional connectivity, including a $1.5-billion investment platform of the US International Development Finance Corporation for Indo-Pacific energy infrastructure.

The secretary added that the US State Department is working with Congress to invest more than $100 million in infrastructure projects supporting the Luzon Economic Corridor, bringing total announced investments for the region to more than $2.5 billion.

Rubio said the United States remains committed to building a partnership with ASEAN based on sovereignty, economic growth and regional stability.