Nearly a month after President Donald Trump announced in a series of tweets that he would ban transgender individuals from serving in the military, the White House is prepared to send guidance to the Pentagon on the implementation of the ban, the Wall Street Journal reported Wednesday night.

Defense Secretary James Mattis will have six months to put the new policy in place, according to the Wall Street Journal. The memo directs the military to reject transgender people who apply to serve and orders the Pentagon to stop paying for medical services for the transgender troops already serving, according to the Wall Street Journal.

The memo gives Mattis some leeway in determining the fate of those transgender people already serving in the military. He will be charged with determining whether transgender individuals are able to serve in a war zone and therefore whether they should be separated from the military, per the Wall Street Journal.

Trump announced the new policy in a late July tweetstorm claiming that he had discussed the policy with his “generals.” However, Pentagon leadership was caught off guard by the announcement. The new policy, an attempt to please the conservative base, drew criticism from several Republican members of Congress, as well as from some military leaders.