The ministry, which is thinking of buying about 40 F-35s, plans to submit a request for their purchase in the fiscal 2011/12 budget, Kyodo said.
It added, however, that the ministry may postpone making the request for one year, due to a view in the government that the purchase should only be made when full details of the plane's capabilities are available.
Lockheed is developing three models of the radar-evading F-35 to replace at least 13 types of aircraft, initially for 11 nations.
Kyodo said each F-35 was estimated to cost about 9 billion yen ($100 million).
Japan is looking to replace its current fleet of aging F-4 jet fighters, whose design dates back to the 1960s, because they have become increasingly difficult to maintain.
Lockheed said last week that it was making progress on the F-35 fighter, the costliest U.S. weapons programme, despite rising costs and delays.
Japan has also been following moves in the U.S. Congress aimed at extending production of Lockheed's radar-evading F-22 Raptor fighter, widely considered the most advanced fighter plane in use today.
Foreign sales of the F-22 were banned by a 1998 law aimed at protecting the 'stealth' technology and other high-tech features. A Senate panel has urged the Air Force to start developing an export model of the F-22.
Apart from Japan, Israel and Australia have also shown an interest in buying the F-22.
(Reporting by Miho Yoshikawa; Editing by Alex Richardson) ((miho.yoshikawa@thomsonreuters.com; +81-3 6441 1854; Reuters Messaging: miho.yoshikawa.reuters.com@reuters.net))($1=88.86 Yen) Keywords: JAPAN USA/F35 (If you have a query or comment on this story, send an email to news.feedback.asia@thomsonreuters.com) COPYRIGHT Copyright Thomson Reuters 2009. All rights reserved. The copying, republication or redistribution of Reuters News Content, including by framing or similar means, is expressly prohibited without the prior written consent of Thomson Reuters.
© 2009 AFX News