The Japanese Foreign Ministry has confirmed the existence of three secret documents Japan signed with the United States related to the war-time protocol that would be used should a contingency break out on the Korean Peninsula.

According to a source in the Japanese government Wednesday, the U.S. and Japan agreed in the documents to allow the U.S. military open use of military bases in Japan in the event that war breaks out in Korea.

The United States, according to the documents, would also be allowed to base nuclear weapons in Okinawa in the event of such a contingency.

Washington has confirmed the existence of the secret documents for some time, but until now, Japan has consistently denied the existence of the materials.