Philippine President Ferdinand Marcos Jr. has expressed significant concern regarding the presence of a Russian submarine, specifically the UFA 490, spotted off the coast of the Philippines in the South China Sea. The submarine was located approximately 148 kilometers (92 miles) west of Cape Calavite, raising alarms about potential intrusions into the Philippines' Exclusive Economic Zone (EEZ) and territorial waters. Marcos described this situation as "very worrisome," emphasizing that any foreign intrusion into Philippine waters is a serious issue for national security.

The Philippine military has taken action by deploying a plane and a warship to monitor the submarine, which reportedly was waiting for favorable weather conditions before continuing its journey to Vladivostok, Russia. Despite the heightened concerns from the government, a spokesperson for the Philippine Navy characterized the incident as "not alarming," although they acknowledged the uniqueness of the submarine, which is armed with a missile system capable of striking targets up to 12,000 kilometers away.

This incident occurs against a backdrop of escalating tensions in the South China Sea, where conflicting territorial claims have led to increased military activities by various nations. The Philippines has been particularly vigilant due to ongoing disputes with China over maritime boundaries in these contested waters.