TOKYO — Japan’s planned upgrade of its Boeing F-15 Eagle fighter jets will involve support from the United States and Boeing, the Japanese Defense Ministry has confirmed.

Shigeyuki Uno, the principal deputy director of the defense planning and programming division of Japan’s Ministry of Defense, told Defense News during an interview at the ministry’s headquarters that the U.S. government and Boeing will provide support for the upgrade through the Foreign Military Sales process, adding that the Japanese defense and aircraft industry will also be involved.

The Defense Ministry requested $89 million to upgrade two of its F-15J/DJ interceptors in its latest budget request for its next fiscal year, presumably to serve as prototypes for the upgrade program. A further $386.7 million was requested for nonrecurring costs for the program.

The upgrades will cover what the budget request describes as “new electronic warfare equipment with the ability to respond to increased capabilities of neighboring countries’ air forces.” The upgrades are also expected to increase the number of missiles Japan’s F-15s can carry, as well as integrate standoff missiles such as the AGM-158 Joint Air-to-Surface Standoff Missile.

Boeing displayed a model of its Advanced F-15 Eagle concept carrying 18 air-to-air missiles at the Japan International Aerospace Exhibition in Tokyo that ended Nov. 30, a significant increase from the maximum of eight carried by the F-15 in its current air defense configuration.

Uno also confirmed that the F-15J’s radar would be part of the upgrade, although the budget request document did not specifically mention that an improved radar will be part of the program.

While Uno did not say so, the new radar will almost certainly be an active electronically scanned array, as Boeing has a clear pathway integrating such radars on the F-15, with U.S. Air Force F-15C/Ds, Singapore’s F-15SGs and Saudi Arabia’s F-15SAs using the Raytheon AN/APG-63(V)3 radar, while American F-15E Strike Eagles are being fitted with the AN/APG-63(V)1 by the same company.

Uno added that Japan’s newer F-15J/DJs, which were originally built to Multi-Stage Improvement Program standards — of which about 88 were further upgraded in the past decade to incorporate additional improvements like Link 16 — will be the first to receive this latest round of improvements.

Japan’s midterm defense program guidelines, set to be released by the end of 2018, are expected to provide more details on this program, including the number of F-15s Japan plans to upgrade.

Mitsubishi built 213 F-15s under license for Japan between 1981 and 1999, of which some 200 remain in service with seven combat squadrons based throughout Japan, and one more acting as a dedicated aggressor unit.