Schools warned to obey transgender toilet rule
The Obama administration has told schools to allow transgender pupils to use the toilets that match their chosen gender identity.
Attorney General Loretta Lynch said it would protect transgender pupils from discrimination and peer harassment.
She said schools may face lawsuits or lose federal aid if they do not comply.
The federal government is fighting the state of North Carolina in court over a law requiring people to use toilets according to their gender at birth.
However, the Obama administration's education and justice departments say public schools must respect transgender pupils' gender identity even if their education records or identity documents indicate a different sex.
"There is no room in our schools for discrimination of any kind, including discrimination against transgender students on the basis of their sex," Ms Lynch said.
Ms Lynch said North Carolina's new state law had echoes of policies of racial segregation and efforts to deny gay couples the right to marry.
However, many have criticised the law as discriminatory.