US Defence Secretary Jim Mattis has said that transgender people already in the military will continue to be allowed to serve pending a study on President Donald Trump’s proposed ban.

“In the interim, current policy with respect to currently serving members will remain in place,” Mattis said in a statement on Tuesday.

He said he would create a panel of experts that would include members of the departments of Defence and Homeland Security “to provide advice and recommendations” on the implementation of the measure, TIME magazine reported.

Trump had announced via Twitter last month that he would no longer allow transgender soldiers to serve in the military, arguing that the government “cannot be burdened with the tremendous medical costs and disruption that transgender in the military would entail.”

The US President signed a memo last week reversing the decision made in 2016 under the Obama administration to allow transgender people to serve in the military, giving the Pentagon six months to come up with a plan for those who are currently serving.

But he left on Mattis to decide whether those already in the armed forces would be allowed to continue to serve.

“The panel will assemble and thoroughly analyse all pertinent data, quantifiable and non-quantifiable,” Mattis said. After the panel provides its recommendations, the Defence Secretary said he will advise the President on implementing this initiative.

“In the interim, current policy with respect to currently serving members will remain in place.”