WASHINGTON — The U.S. Air Force’s top general wants to see the cost of operating and sustaining an F-35 joint strike fighter fall to the same levels as current fourth-generation fighters like the F-16, he told reporters Thursday.

“Our initial target is to get them down to the equivalent or very close to what we’re currently spending to sustain fourth-generation fighters,” Air Force Chief of Staff Gen. Dave Goldfein said during a roundtable.

There could be dire consequences for the F-35 program should operations and sustainment, or O&S, costs not go down as far as desired. On Wednesday, Bloomberg reported that the Air Force could trim its planned purchase of F-35As by a third unless O&S costs decrease by 38 percent over the next 10 years.

On Thursday, Goldfein downplayed speculation that the program could be cut, telling reporters that he continues to be committed to the Air Force’s entire 1,763-unit buy.

“We’re going to be buying these aircraft for a number of years, so it’s way too early to be talking about any curtailment of any procurement or any buy,” he said, adding that any decision to decrease the program of record “is really well out into the future.”

The U.S. Government Accountability Office projected in 2017 that total sustainment costs over the life of the F-35 program could amount to more than $1 trillion during a 60-year life cycle.

Support costs have been increasing as the number of planes and flight hours grow, but the internal Defense Department analysis paper obtained by Bloomberg pointed out that the Pentagon has only “limited visibility” into how the F-35’s manufacturer, Lockheed Martin, spends that money as a contractor.

O&S costs are “absolutely” a major concern, Goldfein acknowledged, and part of the department’s strategy is to pressure Lockheed to lower personnel- and contractor-support costs.

However, “it’s just not true that’s there’s any intent on our part to go one aircraft below the program of record, because that’s what we require today to actually accomplish the [national defense] strategy as its currently written,” he said.

Lockheed trying to lower F-35 cost, says CEO

Lockheed Martin CEO Marillyn Hewson says the company is consciously trying to lower the cost of the Joint Strike Fighter.

The Air Force is the single-largest customer of the F-35, and any decrease in its planned procurement could have a ripple effect that drives up the unit price or O&S costs for the U.S. Navy and Marine Corps, as well as international partners that plan to purchase the Joint Strike Fighter.

However, some of those international customers are also growing concerned about the price of sustaining the aircraft.

During a March 27 roundtable, Stephen Lovegrove, permanent secretary of the U.K. Ministry of Defence, told reporters that the government is pleased with the jet’s performance and is committed to a planned purchase of 138 F-35B short-takeoff-and-vertical-landing aircraft.

But he added that decreasing O&S costs is of “intense interest” to the Britain.

“This is a new platform, and I am constantly being asked by parliamentarians in the U.K. as to what the total cost is going to be, and they are sometimes, understandably, a bit frustrated when I have to turn around and say at the moment: ‘Nobody is entirely sure,’ ” Lovegrove acknowledged.

“But we must maintain an absolutely laser-like focus on keeping those costs down because historically this is the one area where we’ve been OK at buying stuff, but we’ve not been necessarily good at sustaining and operating it as cost effectively as we possibly can. We need to work very, very hard on that, and we are doing so.”

Goldfein is hopeful the Defense Department can drive down the O&S bill with the help of two key players: Ellen Lord, the former Textron CEO who is now the Pentagon’s undersecretary of defense for acquisition and sustainment, and Deputy Defense Secretary Pat Shanahan, a former Boeing executive.

Both officials are “folks who have been out in industry for most of their careers who know how this business works at a level on the industry side and are now helping us wire brush down the cost of not only procurement but also sustainment,” he said. “It gives me a level of optimism in this program that we’re going to be able to get to a pretty good target.”

Aaron Mehta in Washington contributed to this report.