Story highlights The White House said creating a space corps was 'premature at this time'

The idea for a Space Corps was proposed last month by Alabama Rep. Mike Rogers

Air Force leaders immediately came out against the idea

(CNN) The White House and Defense Secretary Jim Mattis are speaking out against a congressional proposal to create a new "Space Corps" dedicated to fighting future wars outside the earth's atmosphere.

The debate over setting up a new military space branch under the umbrella of the Air Force is heating up on Capitol Hill, and the House could vote this week on whether to launch the proposal.

Ahead of the possible vote, the White House said creating a space corps was "premature at this time."

Mattis, in a letter to Rep. Mike Turner -- an Ohio Republican leading the congressional effort against the Space Corps -- said he was opposed to adding "additional organizational and administrative tail" to the Pentagon.

"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.

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