The White House is expected to tell the Pentagon in coming days how to implement a ban on transgender people in the military, according to a memo that says the defense secretary may decide whether to remove service members based on their ability to deploy, a U.S. official said on Wednesday.

The two-and-a-half-page White House document gives Defense Secretary Jim Mattis six months to fully implement the ban, according to a story first reported by The Wall Street Journal and confirmed by the official.

It also directs the Defense Department to deny admittance to transgender individuals and to stop spending on medical treatment regimens for those currently serving, the Journal reported, citing U.S. officials.