President Donald Trump has signed a memorandum restoring a military ban on transgender people that was lifted under President Barack Obama.
The note also terminates the use of state funds for a gender reassignment operation for active staff.
However, President Trump left Defense Secretary Jim Mathis to decide whether to keep the existing transgender recruits.
The reinstated ban, justified on the grounds of costs and interruption, faces a legal challenge from transgender rights activists.
Jennifer Levy, a Glad employee (GLBTQ Legal Advocates & Defenders), said in a statement: “This policy is a shameful slap in the face to people who risk their lives every day to protect our country …
“We are moving quickly with our plaintiffs to see the court stop this latest demonstration by President Trump, who is playing politics with people’s lives.”
It is estimated that between 4,000 and 10,000 American members of the active and reserve service are transgender.
Donald Trump bans US military transgender Rafi Friedman-Gurspan: Obama administration hires first transgender staff member President Donald Trump to repeal gender neutrality rules
After the Obama administration announced in 2016 that transgender people would be allowed to serve openly in the military, many active members came out.
The note was widely awaited after the president’s tweets on the issue last month.
President Trump directed the military to “return to the long-standing policy and practice of military service by transgender people before June 2016.”
Donald Trump suggested that President Obama had not considered whether the policy would “impede military efficiency and lethality. [or] violate the convergence of a unit ”.
The president said he had done the Pentagon a “great favor” by banning transgender troops, saying the issue was “complicated” and “confusing” for the military.
Obama-era policies included a provision for the military to provide medical care to employees who want to change their gender.
In his note, President Trump instructed the Department of Defense and the Department of Homeland Security to stop using government funds for gender reassignment procedures unless necessary.