WASHINGTON (Reuters) - The U.S. Air Force is predicting it will need to grow sharply over the next decade or so, boosting the number of operational squadrons by nearly a quarter to stay ahead of increasingly muscular militaries in China and Russia, officials said.

FILE PHOTO: Three U.S. Air Force F-15E Strike Eagles, from Mountain Home Air Force Base, Idaho, fire flares over the Utah Test and Training Range, west of Salt Lake CIty in Utah, U.S., July 3, 2018. U.S. Air Force/Airman 1st Class Codie Trimble/Handout via REUTERS

Air Force Secretary Heather Wilson told reporters that the preliminary analysis drew partly from classified intelligence about possible threats in the 2025 to 2030 time frame, showing that the service, at its current size, would be unable to preserve America’s edge.”The Air Force is too small for what the nation is asking us to do,” Wilson told a small group of reporters ahead of a speech on Monday that will lay out her arguments.

The Air Force analysis did not include a price tag and Wilson declined to speculate on costs. But such growth could conceivably cost billions of dollars, given the need to hire more personnel and buy substantially more aircraft, from refueling tankers and fighter jets to bombers, made by companies like Boeing Co BA.N and Lockheed Martin Corp LMT.N.

Wilson estimated the Air Force would need about more 40,000 personnel as part of the plan to have a total of 386 operational squadrons, up 24 percent from the 312 today. The increase would bring the Air Force to about 717,000 personnel, including the Guard and Reserve.

The U.S. Air Force had 401 squadrons in 1987, at the peak of the Cold War between the United States and the Soviet Union.

Usually commanded by a lieutenant colonel, squadrons are the core fighting units of the Air Force and are often composed of about 18 to 24 aircraft.

The Air Force estimate is likely to set the stage for greater debate about military spending priorities, including within the Pentagon, where branches of the world’s most powerful military already fiercely vie for resources.

That competition is set to grow if President Donald Trump succeeds in creating a new “Space Force” as the sixth branch of the military, something he hopes to do by 2020.

About one-sixth of U.S. federal spending goes to defense, according to the Congressional Budget Office. Although some lawmakers complain the Pentagon gets too big a share of U.S. resources, defense spending enjoys broad support in Congress.

GROWING RISK

Trump last month signed a massive, $716 billion defense policy bill meant to help address shortcomings in the U.S. military, which is trying to shift its focus to challenges posed by countries like China and Russia after nearly 17 years fighting militants in places like Afghanistan.

Wilson declined to get into details about classified analysis of future military threats.

But she pointed to events already making global headlines, like how Russia staged its largest military exercise this month since the fall of the Soviet Union, mobilizing 300,000 troops.

Pentagon officials believe the bigger challenge, however, will be staying ahead of China’s rapidly expanding military capabilities.

“The threat is growing,” Wilson said. “We have to be clear-eyed about the world in which we live.”

Wilson acknowledged that the Air Force’s estimates would be further refined in the weeks and months ahead. The latest analysis would be among the reports submitted to Congress in March next year that seek to address a basic question: What kind of Air Force America does America need?

Air Force Chief of Staff General David Goldfein noted that was different from the typical question of what is the best Air Force that the United States can afford, given current budget priorities.

Wilson said: “We also know that there will be a debate about what we can afford - and that’s fair.”

“But I think we have to be clear on what is needed to protect our vital national interest in this country,” she said.