The Pentagon says a U.S. military aircraft carrying flag-draped coffins arrived this week at Hawaii's Joint Base Pearl Harbor-Hickam.
History Flight, a Florida-based non-profit group, says its members discovered the remains during excavations on Tarawa, in the Gilbert Islands.
AP reports nearly 1,000 Marines and 30 sailors were killed during the assault on the Japanese-held atoll in November 1943.
History Flight recovered the remains of 35 Marines in 2015. The group says the two recoveries are some of the largest for U.S. battlefield remains since the Korean War.