WASHINGTON — The US Air Force's top general on Wednesday indicated he would be supportive of purchasing low-end attack aircraft to ease the pressure on state-of-the-art fighters deployed to the Middle East.

Asked about Arizona Sen. John McCain's recent suggestion to buy 300 low-cost, light-attack fighters, Air Force Chief of Staff Gen. Dave Goldfein said it was a "great idea" that would help ameliorate growing readiness issues.

"I think we're 15 years into a long campaign in the Middle East. This will continue to be a coalition fight. So we've got to continue to evolve and look at the way we prosecute and sustain this campaign," he said during an event at the American Enterprise Institute (AEI).

In a white paper published Monday, McCain, the Republican leader of the Senate Armed Services Committee, proposed procuring 300 inexpensive, off-the-shelf fighter aircraft, 200 of which could be acquired by fiscal 2022.

"The Air Force should embrace a 'high/low mix' of fighter aircraft. Very expensive fifth-generation technology is not needed in every scenario," McCain wrote in the paper. If the Air Force purchased additional planes to supplement its current inventory, "these aircraft could conduct counterterrorism operations, perform close air support and other missions in permissive environments, and help to season pilots to mitigate the Air Force’s fighter pilot shortfall."

Independent of Congress, the Air Force has been internally debating whether to purchase additional light attack aircraft since mid-2016. The proposed initiative, which goes by the moniker OA-X, is seen by its supporters as a way to accomplish the fight against militant organizations like the Islamic State group at a lower cost per flight hour, while freeing up other assets for training for battles in nonpermissive environments.

Goldfein said it was worth exploring whether the OA-X concept is "a more sustainable model for the future that would be less costly [and] that I could entice foreign partners and allies and coalition members to partner with us on."

Although an OA-X program of record is not yet on the books, Goldfein’s show of support may hint that the service is warming to the idea.

The Air Force chief said he wants to press forward with another idea that has been gaining traction within the service: a flight demonstration of existing, off-the-shelf aircraft, which could pave the way to starting an OA-X program. Lt. Gen. James M. "Mike" Holmes, the service’s deputy chief of staff for strategic plans and requirements, first told Defense News about the proposed experiment last September.

"We don't think [an experiment] would cost a lot of money, and it's designed just to help us get our arms around [questions like]: What can you actually do? Does it actually contribute? Can it survive in different threat environments?" Holmes said at the time.

At AEI on Wednesday, Goldfein said the experiment hasn’t been greenlighted yet, but could occur as early as this spring.

"I am expecting many of the companies to come forward," such as Textron AirLand’s Scorpion jet, he said.