Washington (CNN) The Pentagon has sent a legislative proposal to Congress calling for the establishment of a Space Force within the United States military, a top defense priority for the Trump administration, senior defense officials said Friday.

If authorized by Congress, the proposal would allow for the creation of a sixth service of the military alongside the Army, Navy, Air Force, Marines and Coast Guard. Initially the Space Force would fall under the Department of the Air Force, in much the same way the Marine Corps are formally part of the Navy.

The Secretary of the Air Force would be responsible for organizing, training and equipping two distinct military services, but the new Space Force would have a four-star chief of staff who would serve as a member of the Joint Chiefs of Staff, and a newly created Under Secretary of Space would provide oversight of the civilian component of the new service.

The proposal was submitted to Congress on Wednesday night, and initially makes a request for 200 people and $72 million from the 2020 fiscal year budget to establish a headquarters for the Space Force. Most of the staffing to formally stand up the new service would initially come from the Air Force, with the goal of transitioning personnel from other military branches as the service takes shape over the coming years.

"This is an historic moment for our nation," Acting Defense Secretary Patrick Shanahan said in a written statement Friday. "The Department of Defense's legislative proposal to establish the United States Space Force as the sixth branch of the Armed Forces is a strategic step towards securing America's vital national interests in space. Our approach follows President Trump's bold vision for space and commits resources to deliver more capability faster, ensuring the United States can compete, deter, and, if needed, win in a complex domain."

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