By Liz Lagniton | 2026-06-09

A U.S. Coast Guard cutter joined Philippine naval and coast guard vessels in patrols near Scarborough Shoal, highlighting growing maritime cooperation between Washington and Manila in one of the South China Sea's most contested flashpoints.

The five-day exercise, held from May 26 to 30, marked the first time a U.S. Coast Guard vessel participated in maritime cooperative activities with Philippine forces near the shoal. Philippine officials raised concerns over possible new Chinese structures near the feature. Beijing continues to pose a "severe threat" despite a recent easing in U.S.-China tensions, they said.

The drills involved the U.S. Coast Guard cutter Midgett, Philippine naval frigate BRP Antonio Luna and Philippine coast guard vessel BRP Melchora Aquino. Philippine forces deployed FA-50 fighter aircraft, helicopters and surveillance aircraft, according to the Armed Forces of the Philippines.

The troops performed maritime interdiction and boarding operations aimed at strengthening interoperability and maritime domain awareness, Philippine and U.S. officials said.

"The strength of our partnerships is forged at sea. This exercise provides an invaluable opportunity to hone our maritime law enforcement capabilities and share best practices with our allies," said U.S. Coast Guard Capt. Brian Whisler, commanding officer of the Midgett.

The deployment signaled a broader effort by the Philippines and its allies to counter Beijing's increasingly aggressive maritime activities, Ray Powell, founder and director of the maritime transparency initiative SeaLight, told ABS-CBN.

The patrols took place near Scarborough Shoal, a strategic atoll about 120 nautical miles west of Luzon that China seized after a standoff with the Philippines in 2012. Since then, Beijing has maintained a near-constant presence of coast guard, maritime militia and naval vessels around the area, which lies within the Philippines' Exclusive Economic Zone.

Maritime tracking data published by SeaLight Foundation showed the vessels operated about 35 to 40 nautical miles from the shoal.

"This direct involvement by the USCG [U.S. Coast Guard] in a Philippine challenge to China's maritime aggression inside the West Philippine Sea is a significant step forward for the alliance," SeaLight said in a statement posted on X.

The activity was the sixth maritime cooperative operation between Philippine and U.S. forces this year and the first to include the U.S. Coast Guard, according to the U.S. 7th Fleet. It took place amid repeated confrontations between Manila and Beijing in the South China Sea.

Chinese response

China's military and coast guard responded shortly after the drills concluded. They announced separate patrols near Scarborough Shoal that the People's Liberation Army (PLA) described as countermeasures against "rights violations and provocative acts."

The PLA Southern Theater Command said that conducted naval and air force combat readiness patrols in waters and airspace surrounding the shoal. China's coast guard separately said it carried out law enforcement operations against vessels engaged in "illegal ... activities."

Neither statement identified specific countries.

The latest developments came alongside the Shangri-La Dialogue defense summit in Singapore, where Philippine Defense Secretary Gilberto Teodoro Jr. said Manila remained under pressure from Beijing despite improved relations between Washington and Beijing following a recent Sino-U.S. presidential summit in Beijing.

"We have no choice but really to be resilient and to stand up against Chinese aggression," Teodoro told Reuters on the sidelines of the summit.

The defense chief confirmed the Philippines was investigating preliminary reports of possible Chinese structures being placed near Scarborough Shoal, though he described the intelligence as still "raw."

The Philippine military is actively monitoring developments in the area, Teodoro said.

The reports revived concerns in Manila over a possible repeat of earlier Chinese actions in the South China Sea, where temporary civilian or administrative deployments evolved into permanent military outposts.

In 2025, Beijing declared Scarborough Shoal a "national nature reserve," prompting alarm in Manila that China could tighten administrative control over the disputed feature.

Defense ties

On the sidelines of the Shangri-La Dialogue on May 30, U.S. Secretary of War Pete Hegseth and Teodoro reaffirmed their commitment to the U.S.-Philippines Mutual Defense Treaty.

The two governments signed a 15-year communications interoperability and security agreement aimed at improving secure information sharing between their militaries.

The meetings followed the conclusion of this year's Balikatan exercises, which included expanded training on coastal defense, joint fires and maritime security operations.

Hegseth pledged to transfer a decommissioned U.S. Coast Guard cutter to the Philippines' coast guard to strengthen Manila's maritime capabilities.

"When we look across the region today, there is rightful alarm regarding China's historic military buildup and the expansion of its military activities in the region and beyond," Hegseth said.

Teodoro emphasized Manila's support for bolstered U.S. security partnerships in the Indo-Pacific, saying such cooperation strengthens regional "resilience and deterrence."

Meanwhile, in a June 3 statement, Manila's National Task Force for the West Philippine Sea said it was verifying reports of a possible Chinese structure at the shoal and stressed that the government "takes seriously any development" affecting Philippine sovereignty and sovereign rights in the West Philippine Sea.