Story highlights President Barack Obama signs off on the decision that "has been months in the making," source tells CNN

The United States conducted airstrikes last week to protect two groups after they came under attack last week in Syria

(CNN) Syrian rebels backed by the United States will now have air cover if they come under attack after President Barack Obama signed off on the decision, a senior administration official confirms to CNN on Sunday.

The official said "this has been months in the making."

This comes after the United States conducted airstrikes last week to protect two groups after they came under attack: U.S.-trained rebels and the U.S.-affiliated rebels of the 30th division.

U.S. aircraft came in after the attack on a compound where members of the New Syria Force, which is the U.S.-trained-and-equipped rebel group, were located as well members of the 30th division.

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