WASHINGTON -- The Pentagon office that runs the Lockheed Martin Corp on Monday hailed news that Japan had selected the F-35 as its next generation fighter and said it would help strengthen partnerships with Japan.

"The F-35 Program Office looks forward to strengthening partnerships with Japan, and contributing to enhanced security throughout the Asia Pacific region," the office said in a statement after Japan announced its decision.

Japan is the second country besides Israel to order the F-35 under the U.S. government's foreign military sales program. Lockheed is developing three variants of the radar-evading fighter for the United States and eight partner countries: Britain, Italy, Netherlands, Turkey, Canada, Australia, Denmark and Norway, which have contributed to its development cost.

The F-35 program office said Japan's requirement was for 40-50 new fighters, and the initial letter of agreement will include four conventional takeoff and landing (CTOL) aircraft to be delivered in 2016 with an eighth batch of low-rate initial production planes.

The F-35 will be operated in the Asia Pacific region by U.S. forces, as well as the Royal Australian Air Force, Japan and partner nations involved in multinational military operations.

Japan's selection of the F-35 will allow Japan's air force to operate with the United States and other partner nations, ensuring the future of cooperative deterrence and regional security, the Pentagon office said.