US president Donald Trump has said he will bar transgender people from serving "in any capacity" in the US armed forces.
Mr Trump said on Twitter that after consulting with "generals and military experts" the US government "will not accept or allow Transgender individuals to serve in any capacity in the US Military".
He added: "Our military must be focused on decisive and overwhelming victory and cannot be burdened with the tremendous medical costs and disruption that transgender in the military would entail."
Transgender service members have been able to serve openly in the American military since last year, when former US defence secretary Ash Carter ended the ban.
Military chiefs recently announced a delay on allowing transgender people from enlisting.
However, transgender troops are already serving openly in the military.
After consultation with my Generals and military experts, please be advised that the United States Government will not accept or allow......
— Donald J. Trump (@realDonaldTrump) July 26, 2017
....Transgender individuals to serve in any capacity in the U.S. Military. Our military must be focused on decisive and overwhelming.....
— Donald J. Trump (@realDonaldTrump) July 26, 2017
....victory and cannot be burdened with the tremendous medical costs and disruption that transgender in the military would entail. Thank you
— Donald J. Trump (@realDonaldTrump) July 26, 2017