Secretary of State Marco Rubio, in a memo reviewed by NBC News, said additional guidance would be issued on existing passports containing an “X” sex marker.

The State Department has suspended processing passport applications seeking the gender marker of “X” and will only process and issue passports for people identifying as male or female, according to a department spokesperson.

It is one of the first directives to be implemented after Trump signed a sweeping anti-trans executive order declaring only two sexes, male and female as assigned at birth.