Long an open secret, the U.S. government has for the first time officially acknowledged that nuclear weapons were stored on Okinawa during the Cold War.

In a statement on the Department of Defense's Open Government website, the Pentagon revealed Friday "that U.S. nuclear weapons were deployed on Okinawa prior to Okinawa's reversion to Japan on May 15, 1972."

The Defense Department statement also acknowledged "that the U.S. government conducted internal discussion and discussions with Japanese government officials regarding the possible re-introduction of nuclear weapons onto Okinawa in the event of an emergency or crisis situation."