The United States and the Philippines have begun coordinated maritime patrols in the South China Sea, stepping up joint military activity in one of Asia’s most contested waterways. The move comes as China expands its presence in the area and regional tensions remain elevated.

According to Reuters, the patrols started on Saturday and reflect a tighter security partnership between Manila and Washington. Officials have framed the operations as part of broader efforts to maintain stability and support freedom of navigation in disputed waters.

The South China Sea remains a flashpoint because of overlapping territorial claims by China, the Philippines and other regional states. Frequent confrontations between coast guard and naval vessels have increased the risk of miscalculation and raised concerns among governments that rely on the waterway for trade.

The latest patrols signal that the Philippines is continuing to rely on US backing as it faces pressure at sea. The development is likely to draw close attention in Beijing, where officials have repeatedly objected to expanded US military cooperation in the region.