The White House has given Secretary of Defense James Mattis six months to reinstate a ban on transgenders serving in the military.
The Obama administration lifted the ban in 2016, but President Trump announced in July that it will be reinstated.
"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," Trump tweeted in July.
According to the Wall Street Journal, a White House memo instructs Mattis to put in place guidelines to determine if a transgender person is able to deploy to a war zone, participate in military exercises or serve on a ship for months at a time.
These guidelines will be used to determine if a transgender person should be kicked out of the military.
The memo also tells the Pentagon not to let any more transgenders join the military, and to stop spending money on medical treatments for transgenders already in the service.
LGBTQ advocates say transgenders are no less able to deploy than other military members.
But supporters of the policy say the military's focus should be on winning wars, and the disruption and medical costs of allowing transgenders to serve detracts from that mission.