"The training focused on combined diving and salvage operations, and subject-matter expert exchanges," the Hawaii-based command said on its website. "Divers from both navies also operated together under complex, realistic training scenarios in waters near the Korean Peninsula."

The 33-year-long joint naval practice took place as part of the annual Foal Eagle defense training between the allies.

It especially came as South Korea has just recovered the Sewol ferry, which sank in 2014 off the southwestern coast, with more than 300 people, mostly students, killed.

The South Korean government came under public criticism that it should have quickly mobilized naval divers and the Tongyeong ship, and requested US assistance during the disaster. (Yonhap)