Oct. 30 (UPI) -- Boeing Co. has been contracted to build the Japan Air Self-Defense Force's third and fourth KC-46A tanker planes, a deal the U.S. Air Force said Friday will play an "invaluable role" in security collaborations between the countries.
A $342 million contract modification, revealed on Thursday, calls for the two planes to be completed by 2023.
Boeing won the initial Foreign Military Sales contract to build the planes in 2017, and is expected to deliver the first KC-46A to Japan in 2021.
"This order further enhances our enduring partnership with Japan," said Will Shaffer, Boeing Japan president, in a statement on Friday. "The KC-46 will be an unparalleled asset to Japan's air mobility fleet for decades to come."
The planes bound for Japan will be built on Boeing's 767 production line in Everett, Wash.
Known as the Pegasus, the plane is a military aerial refueling and strategic military transport aircraft based on the 767 passenger aircraft and designed to replace Boeing KC-135 Stratotankers in the U.S. Air Force fleet.
In 2016, the U.S. State Department approved the $1.9 billion sale of four KC-46A refueling tankers and associated equipment to Japan, Boeing's first international sale of the plane.
"Japan's new tankers will play an invaluable role in the security alliance between our two countries," said Col. Jason Lindsey, U.S. Air Force KC-46 system program manager.