President Donald Trump tweeted Wednesday morning that transgender individuals will not be allowed to serve in the U.S. military "in any capacity," saying they would cause "tremendous medical costs and disruption."
Transgender people have been able to serve openly in the military since June 2016, when then-Defense Secretary Ash Carter ended a ban. Trump had tweeted at the time, during the presidential campaign, that he would fight for the LGBT community.
His announcement on Wednesday did not say what would happen to transgender people already in the military.
Trump's Press Secretary Sarah Huckabee Sanders said at an afternoon briefing that the White House and Department of Defense would "have to work together as implementation takes place and is done lawfully."
Asked about Trump's past vow to fight for the LGBT community, Sanders said that the ban was a "military decision" and wasn't a "simple one."
"This was a military decision. This was about military readiness," she said, adding that it was also about "unit cohesion."
At the Pentagon, members of the staff of Defense Secretary Jim Mattis appeared to have been caught off guard by Trump's tweets.
"We refer all questions about the President’s statements to the White House," Navy Capt. Jeff Davis, a Pentagon spokesman, said. "We will continue to work closely with the White House to address the new guidance provided by the Commander-in-Chief on transgender individuals serving the military. We will provide revised guidance to the Department in the near future."
Sanders said that the president's national security team was part of the consultation and Mattis was informed on Tuesday.
The Pentagon's website still said, as of Wednesday morning, that "transgender Service members may serve openly, and they can no longer be discharged or otherwise separated from the military solely for being transgender individuals."
Trump tweeted that after consulting with "Generals and military experts," the 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," he added.
Just last week, when asked about the transgender issue at a Senate hearing, Gen. Paul Selva, vice chairman of the Joint Chiefs of Staff, said, "I am an advocate of every qualified person who can meet the physical standards to serve in our uniformed services to be able to do so." He mentioned no opposition among service chiefs to allowing transgender service.
There are as many as 250 service members in the process of transitioning to their preferred genders or who have been approved to formally change gender within the Pentagon's personnel system, according to several defense officials.
The Pentagon has refused to release any data on the number of transgender troops. A RAND study found that there are between 2,500 and 7,000 transgender service members in the active duty military, and another 1,500 to 4,000 in the reserves.
Two studies — including RAND's — have found health-care cost for transgender service members to be low in the context of the military’s health care budget.
RAND estimated the cost of extending gender transition-related health care coverage for transgender personnel to increase by between $2.4 million and $8.4 million a year, representing a boost of between 0.04 percent to 0.13 percent.
Another from the New England Journal of Medicine in September 2015 called "Caring for Our Transgender Troops — The Negligible Cost of Transition-Related Care" said: "When it was announced that the U.S. military anticipates lifting its ban on service by transgender persons, critics expressed concern about the cost of providing transition-related care. But the cost will be negligible in the scheme of the military's health care budget."
Republican John McCain, the chairman of the Senate Armed Services Committee, said in a statement that Trump's tweet "is yet another example of why major policy announcements should not be made via Twitter."
“The statement was unclear. The Department of Defense has already decided to allow currently-serving transgender individuals to stay in the military, and many are serving honorably today," he said in a statement. "Any American who meets current medical and readiness standards should be allowed to continue serving. There is no reason to force service members who are able to fight, train, and deploy to leave the military—regardless of their gender identity."
McCain added that no new policy decision would be appropriate until a Defense Department study is complete and vowed Senate oversight on the issue.
"I don't think we should be discriminating against anyone," Utah Republican Sen. Orrin Hatch said in a statement. He said he planned to get clarity from the military.
Trump's decision earlier drew immediate angry responses from groups that represent transgender service members.
Matt Thorn, executive director of OutServe-SLDN, which represents the LGBT population in the military, said thousands have been serving in the U.S. armed forces without causing any issues.
"It's an absolute absurdity and another overstep," Thorn said. He threatened legal action if Wednesday's decision is not reversed.
Victoria Rodriguez-Roldan, director of the Trans/Gender Non-Conforming Justice Project, National LGBTQ Task Force, said Trump "has stood against the trans community with this decision and is harming lives for the sake of political gains."
"The military is often the last resort for people who can't find jobs because of discrimination," Rodriguez-Roldan said. She said the transgender community "will not stop fighting" for justice.
Trump's tweets also prompted fierce backlash from prominent Democrats and other supporters of transgender service members.
The "decision to ban transgender Americans from the military is a vile attack on brave individuals defending our country," House minority leader Nancy Pelosi said.
Senate Democratic leader Chuck Schumer said transgender Americans "are serving honorably in our military. We stand with these patriots."
Sarah McBride, a spokesperson for the LGBT advocacy group Human Rights Campaign, wrote, "A man who received 5 deferments from Vietnam is threatening the careers of 15,000 trans troops. Reprehensible, unpatriatic, and dangerous."
Others on social media noted that Trump's decision falls on the anniversary of President Truman's action on July 26, 1948, to end racial segregation in the armed forces.
Some conservative organizations and lawmakers hailed the decision.
Family Research Council President Tony Perkins applauded Trump for "keeping his promise to return to military priorities — and not continue the social experimentation of the Obama era that has crippled our nation's military."
Rep. Steve King, R-Iowa, said Trump's supporters "will be happy to hear it. We don't need to be experimenting with the military. Plus there's no reason to take on that kind of financial burden."
Since Oct. 1, transgender troops have been able to receive medical care and start formally changing their gender identifications in the Penatagon's personnel system.
But Carter also gave the services until July 1 to develop policies to allow people already identifying as transgender to newly join the military, if they meet physical, medical and other standards, and have been stable in their identified genders for 18 months.
On the eve of the deadline, Defense Secretary Jim Mattis announced a delay on allowing transgender people from enlisting, giving the armed forces another six months to study the issue.
Key concerns include whether currently enlisted troops have had medical or other issues that cause delays or problems with their ability to deploy or meet physical or other standards for their jobs. Military leaders also wanted to review how transgender troops are treated, if they're discriminated against or if they have had disciplinary problems, the officials said. They were not authorized to discuss internal deliberations publicly so spoke on condition of anonymity.
The Republican-led House narrowly rejected a measure earlier this month that sought to strike an Obama-era practice of requiring the Pentagon to pay for gender transition surgeries and hormone therapy.
“Thousands of transgender Americans are currently serving in uniform and there is no reason to single out these brave men and women and deny them the medical care that they require,” former Chairman of the Joint Chiefs of Staff Adm. Mike Mullen told USA Today this week.
Mullen oversaw the repeal of “Don’t Ask, Don’t Tell” in 2011.
Missouri GOP Rep. Vicky Hartzler, who authored the amendment to end the funding, was among those who cheered Trump's decision on Wednesday.
"I'm pleased to hear that President Trump shares my readiness and cost concerns, and I'm glad to hear the president will be changing this costly and damaging policy," she said in a statement. "Military service is a privilege, not a right. We must ensure all our precious defense dollars are used to strengthen our national defense. Now, we can focus on rebuilding our military and addressing the growing threats around the world."