The U.S. Department of Defense (DOD) on Wednesday highlighted its strengthening defense ties with the Philippines after conducting its most complex underwater mission in the country to date.

During a virtual press briefing, Kelly McKeague, director of the Defense POW/MIA Accounting Agency (DPAA), said the agency began an underwater excavation project in February to account for Americans linked to the sinking of the Oryoku Maru.

The Oryoku Maru, a Japanese prisoner-of-war transport ship, was destroyed in Subic Bay during World War II.

“In February, we began our largest, most complex underwater mission ever in the history of this mission, which dates back to 1985,” McKeague said.

The ship was mistakenly bombed by U.S. Navy aircraft in December 1944. At the time, the unmarked vessel was carrying more than 2,500 Allied prisoners of war being transported from the Philippines to Japan.

“When the ship was sunk, it limped back into Subic Bay and it sank there,” McKeague said, adding that the team began efforts three years ago to investigate the site underwater and examine the wreckage.

“Using these cutting-edge underwater vehicles, [w]e created a three-dimensional image of the ship that then allowed us to begin excavation.”

McKeague said the agency estimates that more than 250 missing Americans remain in the hold of the ship.

“We think they might be limited to one of two holds, and that’s where the divers are currently operating on,” he said, noting the mission has benefited from cooperation with the Armed Forces of the Philippines (AFP).

Teams deployed

McKeague said the DPAA has no missions in the Visayas or Mindanao but continues year-round operations in the Philippines, with teams in Leyte, Luzon and Mindoro.

He emphasized that most missions are conducted on land, with support from the AFP, the National Museum of the Philippines, and local government units.

“The support that we receive from the entire Philippine Government is truly — like, truly extraordinary. I believe it helps strengthen the alliance that we have forged between the United States and the Philippines,” he said.

McKeague announced they will conduct a scientific summit soon this year, bringing together representatives and scientists from 16 Indo-Pacific nations.

“In the past, the National Museum of the Philippines, the National Museum of Papua New Guinea, Solomon Islands, Malaysia, Indonesia — all of these countries come together, and we’re very excited about the summit. [M]ore information will be coming out from that,” he said.

The DPAA is a DOD agency responsible for recovering and identifying unaccounted personnel listed as prisoners of war (POW) or missing in action (MIA) from past conflicts worldwide.