President Donald Trump's idea to form a Space Force is a "bold idea," but the United States already has control over the space above planet Earth, Air Force Secretary Heather Wilson told CNBC Wednesday.

Wilson, who admitted the U.S. is trying to prevent other nations from stopping America's use of the front, called the Space Force "a bold idea to dominate in space," and said "the Air Force has a lot of authorities now to continue to accelerate defendable space so that we dominate and win. We're the best in the world at space. Our adversaries know it, and they're developing the capabilities to deny us the use of space in crisis or war and we are determined that that not be allowed to happen."

Trump first raised the idea of forming the Space Force in March during a speech in front of Marines. Wilson and others in the military have been mostly supportive of it.

Earlier this month, Wilson called the idea "forward-looking" and pledged to follow through with a proposal for the fiscal year 2020 budget.

It's estimated that the Space Force would cost $13 billion over the next five years.

• NASA Chief: Agency Will Launch Astronauts Into Space From U.S. Soil in 2019
• Inhofe Warms Up to Idea of New Military Branch - if Price is Right