The U.S. Navy won't alter its so-called "freedom of navigation" sail-bys in the disputed South China Sea and has pressed ahead with such operations despite a dangerous maneuver by a Chinese ship against an American destroyer.

Vice Adm. Phillip Sawyer, commander of the U.S. 7th Fleet, told reporters in Manila on Monday that Washington protested that "unprofessional behavior" by the Chinese ship, which maneuvered very close to the USS Decatur as the latter sailed closely by a Chinese-occupied island in the Spratlys in September.

Sawyer said the U.S. Navy will continue such sail-bys and patrols in the South China Sea and elsewhere "until there are no excessive maritime claims throughout the world."

Sawyer spoke onboard the USS Blue Ridge, which arrived in Manila after sailing through the South China Sea.