Air Force leaders dodge questions on Trump's 'Space Force' The idea of a space command has long been debated by Congress and the military.

Top Air Force leaders sidestepped questions from Congress this morning about the creation of the "Space Force" suggested by President Donald Trump Tuesday.

Air Force Secretary Heather Wilson opened her testimony before the House Appropriations Committee today by touting the Air Force's efforts in space, a top priority for the service in the fiscal year 2019 budget.

In contrast, Trump suggested removing the space domain out of the Air Force and creating a separate Space Force.

"My new national strategy for space recognizes that space is a war-fighting domain, just like the land, air, and sea. We may even have a Space Force -- develop another one: Space Force," Trump said at Marine Corps Air Station Miramar in San Diego. “We have the Air Force; we'll have the Space Force. We have the Army, the Navy.

“You know, I was saying it the other day, because we are doing a tremendous amount of work in space. I said maybe we need a new force. We'll call it Space Force. And I was not really serious. Then I said what a great idea. Maybe we'll have to do that. That could happen."

When asked for her reaction to the idea, Wilson would only say she welcomed the president and vice president's leadership on space operations.

Sitting beside the secretary, Air Force Chief of Staff Gen. David Goldfein said he was "excited by the dialogue."

The idea of a separate space command has long been debated in the military and on Capitol Hill. The Space Corps -- as it's been called -- was in the House's version of the 2018 National Defense Authorization Act but later dropped in conference.

Advocates for a Space Corps say a separate command is necessary to keep up with modern adversaries like China and Russia.

But in a letter last summer to Rep. Mike Turner, R-Ohio, who spearheaded the congressional effort against the Space Corps, Secretary of Defense James Mattis said he was opposed to the idea.

"At a time when we are trying to integrate the department's joint warfighting functions, I do not wish to add a separate service that would likely present a narrower and even parochial approach to space operations," Mattis wrote.

Testifying today before the House Armed Services Committee, the former deputy assistant secretary of defense for space policy also pushed back on the creation of a separate Space Corps.

"Space is a different kind of domain than air," Doug Loverro told congressman during a hearing on space warfighting readiness. "We don't need to move it out of the Air Force in order to go ahead and create the space-smart civilian and military force that we need.

“But we need to allow it to grow differently than the way we would grow air officers."

He compared it to how the Navy has different training for a sailor operating submarines versus ships in the surface fleet.

ABC News' Ben Siegel and Luis Martinez contributed to this report.