"In view of budgets and production schedules, a new acquisition of around 25 planes is appropriate," a Japanese official told Reuters Wednesday.
By purchasing some of the aircraft directly from Lockheed's US-based plant, the Japanese government could save about $30 million per plane.
Thirty-eight of the 42 F-35A aircraft Tokyo has already purchased are being constructed at the Mitsubishi Heavy Industries plant in Komaki, Japan.
Tokyo has also reportedly considered plans to obtain F-35B aircraft, the F-35 variant capable of short takeoffs and vertical landings on smaller aircraft carriers or helicopter carriers.
In late December, the Japan Times reported that the Japanese Maritime Self-Defense Force was considering whether the fleet's Izumo-class vessels could conduct F-35B operations in addition to naval helicopter operations.
Japanese Defense Minister Itsunori Onodera pushed back against the report, however, telling reporters that "no concrete examination is under way on the introduction of [the] F-35B or remodeling the Izumo-class destroyers."
Japan's first F-35A aircraft are deployed in northern Japan to conduct surveillance on North Korea and protect Japanese airspace.