President Donald Trump on Wednesday announced that the United States would no longer allow transgender people to serve in the military.

Trump said that American military forces must be focused on decisive and overwhelming victory and couldn’t accommodate transgender people.

In what has become Trump protocol, he announced the decision to the American people in a series of Twitter posts, saying his decision came after talking to military experts and generals.

“After consultation with my Generals and military experts, please be advised that the United States Government will not accept or allow transgender individuals to serve in any capacity in the U.S. Military. Our military must be focused on decisive and overwhelming victory and cannot be burdened with the tremendous medical costs and disruption that transgender in the military would entail. Thank you,” the president said in a series of Tweets.

The policy change was met by outrage from advocacy organizations, praise from conservatives and surprise from the U.S. Pentagon.

The change reverses administration changes from President Barack Obama, who made it a rule to accept transgender people in the military last year.

Pentagon officials told members of the media they were caught off guard and had been studying the effects of transgender troops on other service members, but had not shifted their view toward removing transgender people from the military.

Longtime Alabama Sen. Richard Shelby told CNN, “You ought to treat everybody fairly and give everybody a chance to serve.”

He also released a statement about Trump’s policy change.

“We are a nation at war. I am confident that (Defense) Secretary (James) Mattis and DoD leadership can and will evaluate current personnel policy that will enable us to recruit, train, and equip and all-volunteer force. Any American who wants to serve our country and is able to meet these standards should have the opportunity to do so.”

Shelby, who serves on the senate defense appropriations committee, said he anticipated there will be congressional hearings regarding the president’s new policy.

Alabama Sen. Luther Strange had a different view.

“The U.S. Military is no place for social experiment,” he said. “As a member of the senate armed services committee, my first priority is to ensure the readiness of our military. President Trump’s concerns are well-founded, and I support reexamining any DoD policy that may hinder the ability of America’s fighting forces to execute their missions effectively.”