U.S. officials tentatively have connected one of the sites to a C-46 transport lost on March 27, 1944, on a flight from Kunming, China, to Sookarating in northeastern India. The plane's crew of four is still listed as missing in action.
Officials declined to provide identities of the four men pending notification of relatives that their remains might be recovered from Milin County in the Lang Gong Region for identification by U.S. forensic experts in Hawaii.
Pentagon officials said little was known about the second crash site and that specialists of the Defense POW/Missing Personnel Office (DPMO) would check World War II records in an attempt to match up known mission profiles and missing U.S. aircraft.
China first provided information on the two crashes to U.S. military officials during a meeting last fall, then sent updated information on the crashes through the U.S. Embassy in Beijing last month.
''The Chinese government has previously provided generous assistance to the United States in recovery operations of World War II aircraft,'' the Pentagon said in a statement.
In 1994, it said, the Chinese notified the United States of a crash site discovered on Tibet's Ruo Guo Glacier from which U.S. specialists recovered and identified the remains of five American crewmen.
During 1997-99, the Chinese assisted U.S. specialists in the recovery of remains from a World War II B-24 bomber crash in southern China. All 10 crew members were identified, returned to the United States and buried with military honors.