Military officials have taken "significant strides" in moving the fighter from the testing and development stage into full production, DD spokesman George Little told reporters on Tuesday.
That "emerging stability" within the F-35 effort is a positive sign the United States and its allies "will get over the goal line" on the JSF, Little said during Tuesday's press conference.
A recent Pentagon assessment of the program released in March puts the F-35 price tag at $1.51 trillion — that figure represents a 9 percent increase compared to the program's cost estimates from a year ago.
DOD's March assessment includes both estimated production and sustainment costs over the life of the fighter.
That growth has been widely attributed to development delays tied to engineering problems uncovered in the jet during testing.
Controlling costs and getting those engineering problems resolved is "something we have to get our arms around" before moving to full-on production of the fighter, Little said.
"We have to tighten up," he added. "We don't like to see cost increases."
However, Little defended the program, saying program officials have largely moved past many of the major engineering issued plaguing the fighter.
That progress, despite the recent report of cost growth in the effort, will keep the fighter on track to become a part of U.S and partner nation fleets.
But that pool of partner nations could get a lot smaller over the next couple of years.
Two key members of the JSF's nine-member international coalition are considering ramping down their participation or leaving the program altogether.
Ottawa is reassessing its future role on the F-35 program in light of a scathing report claiming Canadian defense officials failed to inform top government decision makers "of the problems and associated risks" with buying the F-35.
Severe defense spending cuts in the United Kingdom already have London throttling back its planned purchases of the F-35.
Canada and the United Kingdom, along with Australia, are considered the strongest members of the JSF alliance.
The current fiscal crisis sweeping across Western Europe could also threaten the future roles of the remaining partner nations.
The other JSF partners are the Italy, the Netherlands, Turkey, Denmark and Norway.
Italy could join Greece and Ireland as the latest recipient of an European Union-financed bailout.
Officials from German Chancellor Angela Merkel's administration on Tuesday ruled out Spain as the next EU member to need a bailout, according to Reuters.
However, the steps being taken by Madrid to shrink the country's debt will likely make it difficult to pay for a large-scale JSF buy.
Partner nation participation in the JSF program "will clearly [be] put at risk if all the predictions about an [European] economic collapse would occur," Chairman of the Joint Chiefs of Staff Gen. Martin Dempsey said last December.
Little acknowledged that "certain [economic] pressures ... in certain parts of the world" were having an impact on the JSF international coalition. But military leaders on both sides of the Atlantic are aware "of the capabilities of this program" which will play a critical national security role in the U.S. and overseas, Little said.
The ongoing difficulties among the JSF partner nations would not force DoD to reconsider its vehement support of the fighter, according to Little.
"We are not running toward the exits" on the F-35, he said.