Lockheed Martin Corp’s F-35 fighter jet is on track both to meet the Marine Corps’s July target to declare the jet ready for combat use and to meet the Air Force’s target date a year later, top U.S. military officials said Thursday.

The F-35 B-model, which can take off from shorter runways and land like a helicopter, was making good progress and should meet the Marine Corp’s target for initial combat use, Navy Secretary Ray Mabus told reporters after a speech at the annual conference of the Surface Navy Association.

Air Force Chief of Staff General Mark Welsh told a separate news conference at the Pentagon that he was confident the Air Force would meet its target date of declaring the F-35 A-model ready for initial combat use by August to December 2016. […]