The Obama administration has issued a "guidance" to all public schools telling them to open their showers, locker rooms, and restrooms to all their transgender students who want to use those facilities that match their gender identity.

The joint eight-page letter issued by the Departments of Education and Justice released on Friday states that compliance to this directive will serve "as a condition of receiving federal funds," LifeSite News reports.

The directive also states that schools should not require a "medical diagnosis or treatment" before accepting a student's transgender self-identification.

The moment a child's parent or guardian says the child identifies as a member of the opposite sex, the school must recognise that," the letter says.

Schools cannot require a transgender student to use separate facilities, although they may allow students who object to the new arrangement to use individual restrooms or changing facilities, the letter states.

Moreover, the letter also instructs school administrators to allow members of one biological sex to stay overnight in the same rooms or dormitories as members of the opposite sex, if the former identify as transgender.

"No student should ever have to go through the experience of feeling unwelcome at school or on a college campus," U.S. Education Department Secretary John King Jr. said earlier. "We must ensure that our young people know that whoever they are or wherever they come from, they have the opportunity to get a great education in an environment free from discrimination, harassment and violence."

The letter also includes a 25-page document detailing the "emerging practices" that are observed in many schools in the U.S. including installing privacy curtains or allowing students to change bathroom stalls.

Justice and Education Department officials said the letter is in response to inquiries by educators, parents and students about how to treat transgender students.

"Schools want to do right by all of their students and have looked to us to provide clarity on steps they can take to ensure that every student is comfortable at their school, is in an environment free of discrimination, and has an opportunity to thrive," wrote Catherine Lhamon, assistant secretary of education for civil rights, and Vanita Gupta, head of the Justice Department's Civil Rights Division.

The Obama administration is pushing for transgender rights following the U.S. Supreme Court decision legalising same-sex marriage in June last year.

The letter is expected to draw criticisms from Republicans following the controversy surrounding House Bill 2 law in North Carolina.

North Carolina Gov. Pat McCrory filed a lawsuit against U.S. Justice Department which told the state that HB 2 violated civil rights law. As response, the Justice Department also filed a lawsuit to stop the implementation of the bathroom law.

Republicans have defended the North Carolina law, saying it is inappropriate for transgender women to use restrooms used by young girls.