Has Pentagon approved US Navy's next-generation fighter?

Beyond the funding dispute, there was also debate during the months-long delay about whether defense contractors Northrop and Boeing would struggle to make the jet on schedule.

Defense officials debated whether Boeing could employ enough engineers for the project after it was awarded a contract to build the US Air Force's F-47 jet in March, sources said. They also debated whether Northrop would strain under the ballooning costs of the Sentinel intercontinental ballistic missile program, aimed at replacing the aging Minuteman III missiles, the sources said.

The quantity of F/A-XX jets, the value and exact timelines of the program remain classified, but previous such contracts - such as that for the F-35 - have been worth tens of billions of dollars over their lifetime.