The government will allow domestic defense-related manufacturers to participate in production of F-35 stealth fighters for the Air Self-Defense Force, according to sources.

The government, which will sign contracts with the manufacturers in August, is aiming to solidify Japan-U.S. security relations while nurturing the domestic defense industry, the sources said Wednesday.

The F-35 is to be the ASDF's next-generation mainstay jet.

The move came after Chief Cabinet Secretary Yoshihide Suga said in March that while the Abe administration will maintain Japan's long-standing ban on exporting arms, it has decided to allow domestic companies to make parts for the F-35 on the belief that the United States, which is chiefly responsible for development of the jet, will strictly control shipments.

Among the firms, Mitsubishi Heavy Industries Ltd. is expected to conduct final assembly, IHI Corp. to make engine parts and Mitsubishi Electric Corp. to make radar components.

Prior to signing contracts, the government is expected to reach a formal agreement with Washington to purchase two F-35s for the ASDF in the fiscal 2013 budget.

Japan has already completed negotiations with the U.S. to buy the two jets for less than ¥29.9 billion in total, the amount earmarked in the 2013 budget. They are to be delivered in March 2018.