The United States failed to deliver 46.1 billion yen worth of defense equipment to Japan as of the end of fiscal 1997, despite Japan's advance payment, a Board of Audit report showed Friday.

Delivery of the U.S. military supplies, which were ordered by the Defense Agency under the U.S. Foreign Military Sales framework, is more than a year behind schedule, the report says.

FMS are Pentagon-negotiated deals through which the U.S. sells defense equipment to its allies. Of some $21.1 billion that went into the U.S. coffers through arms exports to the world in fiscal 1997, $19.2 billion was secured through FMS deliveries, according to the U.S. Department of Defense.

Purchasing a U.S military product through FMS usually costs an allied nation less than domestically producing a similar one or buying the same item through first inking a contract with the manufacturer because the order is dealt with as part of the Pentagon's equipment procurement program.

The Board of Audit report, submitted to Prime Minister Keizo Obuchi Friday morning, says the yet-to-be-delivered goods include parts for 77-mm rocket bombs used by the Ground Self-Defense Force and communication components for the Air Self-Defense Force's E-2C early warning aircraft.