US Education Secretary Betsy DeVos has come under pressure from Democrats over the Trump administration's decision to roll back protection for transgender students.
A number of Democrat members of the Senate Health, Education, Labor and Pensions Committee, including Massachusetts senator Elizabeth Warren, sent DeVos a letter panning the administration's "disturbing" decision.
The letter, seen by The Hill, read: "All students – no matter their race, religion, disability, country of origin, sex, sexual orientation, or gender identity – deserve to have their civil rights vigorously enforced and access to education free from discrimination fiercely protected."
The protections for students included permitting transgender students to use the bathrooms that match the gender they identify as, rather than their gender at birth – protections that the administration believes should be up to individual states or local governments to decide.
Taking such steps has caused concern among some who believe transgender students will be at risk of discrimination if states choose not to retain the protections put in place during former president Barack Obama's tenure.
DeVos has not yet issued a response to the letter, although she has been given until 24 March to respond to questions on the Education Department's view on protection of students.
The education secretary has previously defended the rescinding of Obama-era protections for transgender students.
Appearing at the Conservative Political Action Conference (CPAC), DeVos said that the protections had been "a very huge example of the Obama administration's overreach", calling them an attempt at a "one-size fits all" policy and arguing that the decision should be made at state and community levels.