Arizona Sen. John McCain called President Donald Trump’s tweets banning transgender Americans in the military “unclear,” and said that Trump should have waited until a review of the issue is completed.

“The statement was unclear,” McCain, chair of the Senate Armed Services Committee, said Wednesday. “The Department of Defense has already decided to allow currently-serving transgender individuals to stay in the military, and many are serving honorably today.”

“Any American who meets current medical and readiness standards should be allowed to continue serving.”

He continued stating that there is no reason to force those in the military who are able-bodied to leave, regardless of their gender identity.

“We should all be guided by the principle that any American who wants to serve our country and is able to meet the standards should have the opportunity to do so — and should be treated as the patriots they are,” McCain said.

A 2016 study commissioned by the Department of Defense found that transgenders serving in the military would “have minimal impact on readiness and health care costs” due to the small number of transgender servicemembers. That study and other factors continue to be reviewed by Secretary James Mattis.

“I do not believe that any new policy decision is appropriate until that study is complete and thoroughly reviewed by the Secretary of Defense, our military leadership, and the Congress.”