One of the three, U.S. Air Force Sgt. Donald Michaud, will be buried Friday with full military honors in Biddeford, Maine, a statement said.
The remains of Michaud, along with Airman Jan Granroth and her brother Mark Granroth, were identified after DNA analysis by the U.S. Department of Defense Armed Forces Medical Examiner.
Donald Michaud had been stationed at a U.S. military base near Athens when he disappeared, along with the two other divers, while exploring undersea caves in Lake Vouliagmeni, near Athens, on Sept. 9, 1978.
The lake, a rock-encrusted basin of thermally-heated, brackish water near the coast south of Athens, is known for its dangerous maze of underwater caves and unpredictable currents.
Michaud, who was 32, was survived by his wife, Rosemary, and their three children, Yuni, Robert and Katherine.
Funerals for the other two divers will be held August 4 in Sebeka, Minnesota, also with full military honors, the embassy said.
The divers' remains were recovered last year by Greek volunteer divers who had been searching for a missing Greek photographer, who disappeared in Lake Vouliagmeni in 1990.
After failing to match the remains to the missing photographer, Greek authorities turned them over to the U.S. military, which used DNA analysis for identification.
Having killed Iranian general Qasem Soleimani, the United States has canceled all international laws and treaties, all personal rights of any person and entire nations