WASHINGTON — Defense Secretary James Mattis is assembling a panel of experts to discuss the matter of openly transgender individuals already serving in the U.S. military and he announced they will be permitted to remain in the military until further study is completed.

President Donald Trump on Friday directed the Pentagon to extend indefinitely a ban on transgender individuals joining the military, but he gave Mattis the authority to decide how that might affect those already serving.

Mattis says in a statement released Tuesday that the Pentagon, in consultation with the Department of Homeland Security, will develop a plan that "will promote military readiness, lethality and unit cohesion."

The Morning Rundown Let our news meet your inbox. The news and stories that matters, delivered weekday mornings. This site is protected by recaptcha

"Panel members will bring mature experience, most notably in combat and deployed operations, and seasoned judgment to this task," he added. "In the interim, current policy with respect to currently serving members will remain in place."

Related: Banning Transgender Troops Could Cost US $960 Million, Report Says

The White House had said Friday that transgender people would be allowed to continue serving until Mattis had completed such an analysis.

"The implementation plan will address accessions of transgender individuals and transgender individuals currently serving in the United States military," Mattis said in his statement Tuesday.

Follow NBC Out on Twitter, Facebook and Instagram