US and Philippine defense chiefs signed an agreement on Monday to share classified military information and technology, strengthening their long-standing alliance as they seek what they perceive as China's influence in the region.

US Defense Secretary Lloyd Austin and Philippine Defense Secretary Gilberto Teodoro signed the General Security of Military Information Agreement, which enables the sharing of classified information that could enhance national defense and facilitates the sale of certain classified technologies, officials noted.

Although Austin and Teodoro did not make public statements during the signing ceremony, the Philippine defense department called the agreement “a critical step to enhance information sharing and deepen interoperability between the Philippines and the US."

The big picture 

This escalation has raised concerns that the United States could be drawn into a war under its mutual defense treaty with the Philippines.

Following the signing, Austin is scheduled to visit the western island of Palawan on Tuesday to meet with Filipino forces responsible for patrolling the South China Sea and defending outposts.

China has viewed joint military drills and new pacts as provocative actions aimed at containing its influence in the region. Recently, it has intensified its military activities in the South China Sea, conducting a series of drills that have heightened regional tensions.

Notably, China has expanded its coast guard fleet, deploying the world's longest patrol ships, such as the Haijing 5901 and Haijing 2901, to enforce its territorial claims in disputed waters.