President Donald Trump announced Wednesday that transgender people may not serve "in any capacity" in the US military, citing the "tremendous medical costs and disruption" their presence would cause.

In late June, Pentagon chief Jim Mattis had delayed for six months a plan put in place under Barack Obama's administration to start accepting transgender recruits. 

An estimated 2,500 to 7,000 transgender people are among the 1.3 million active duty service members.