Senate Armed Services Chairman John McCain decried President Trump's Friday order for the Pentagon to ban transgender people from entering the military.

"It would be a step in the wrong direction to force currently serving transgender individuals to leave the military solely on the basis of their gender identity rather than medical and readiness standards that should always be at the heart of Department of Defense personnel policy," McCain, R-Ariz., said in a statement late Friday.

"The Pentagon's ongoing study on this issue should be completed before any decisions are made with regard to accession. The Senate Armed Services Committee will continue to conduct oversight on this important issue," McCain added.

Earlier Friday evening, Trump issued a directive for the Pentagon to suspend plans to recruit transgender troops, including stopping medical treatment and deciding over the next six months if current troops can remain in the military.

"In President Trump's judgment, the previous administration failed to identify a sufficient basis to conclude that terminating the DOD and DHS long-standing policy and practice would not hinder military effectiveness or lethality, disrupt unit cohesion, tax military resources, etc.," an official told reporters about Trump's memo.

Trump first announced the decision in a tweet a few weeks ago.

Five transgender service members have sued the Trump administration over the new policy.