Secretary of State Marco Rubio directed the State Department on Wednesday to suspend all passport applications seeking to change a sex marker and all applications requesting an “X” sex marker, according to a memo reviewed by NBC News.  The memo references an executive order issued by President Trump hours after his inauguration, declaring that the U.S. government will recognize only two sexes, male and female, and that “these sexes are not changeable and are grounded in fundamental and incontrovertible reality.”  “The executive order specifies government-issued identification documents shall refer to an individual’s immutable biological classification as either male or female,” Rubio’s memo states. “In agency documents ‘sex’ and not ‘gender’ shall be used. Further, it is specified that the policy of the United States is that an individual’s sex is not changeable.” Trump Administration 8 hours ago Trump administration gives green light to start firing federal workers in DEI roles news 19 hours ago Trump recommends ending FEMA ahead of California fire site visit As a result, the memo continues, the State Department will no longer issue “X” sex markers for U.S. passports or birth records for U.S. citizens with children born abroad. It directs employees to suspend all applications requesting an “X” sex marker or a sex marker change, adding that employees should “not take any further action” on those applications “pending additional guidance from the Department.”  The memo applies to all applications currently in progress and any future applications, the memo states, adding that guidance on existing passports containing an “X” sex marker “will come via other channels.” In an email to NBC News, the State Department confirmed that it is “no longer issuing U.S. passports with X markers” and that it has “suspended processing of all applications seeking a different sex marker than that defined by the terms” of Trump’s executive order pertaining to gender. The spokesperson did not answer questions regarding whether passports that currently have an “X” marker are still valid or what will happen if people travel with them but said updates are forthcoming and would be shared as soon as possible the department’s travel website. The uncertainty surrounding how Trump’s executive order would affect passports has caused fear and confusion among some transgender people who have shared on social media that they have passport renewal applications in process with the State Department.  Amy, who has a transgender son and asked to go by her first name to protect her family’s privacy, said she submitted an application to correct the sex marker on her teenage son’s passport, and it was delivered Tuesday, according to postal service tracking. She said she’s called every day since to check on its status, and that, as of Friday afternoon, all of the employees she’s spoken with have told her that they are processing requests to update gender markers as usual. However, after hearing news of Rubio’s memo, she said she’s “devastated.”  She’s concerned her son’s passport application will be suspended and that his valid passport, which has his previous legal name and sex marker and was sent as part of his application, will be held in the processing center at least until the State Department issues new guidance. “We put these forms in so that everyone in our family would have a valid passport, because that seemed suddenly very necessary,” she said, noting that access to gender-affirming care for minors is changing rapidly across the country. “We didn’t know if we would need to leave the country to get medical care, and for our son’s valid passport to be held with no indication of when we might get that back feels not legal and terrifying.”  A day after Trump — who has promised to ban gender-affirming care for minors nationally — issued the executive order pertaining to gender, the department removed a page from its website titled “Selecting your gender marker.” The page, which still appears in Google search results, said that people applying for or updating a passport could select male (M), female (F), unspecified or another gender identity (X) as the gender marker on their U.S. passport books and cards. “We promote the freedom, dignity, and equality of all people — including LGBTQI+ individuals,” the page said. “We are demonstrating this commitment to better serve all U.S. citizens, regardless of gender identity.” The since-removed page also provided information about traveling as an LGBTQ person and cautioned that those with “X” gender markers might not be able to travel to all countries. As of Tuesday afternoon, the page redirected to a general passport information page. Trump’s executive order regarding gender and identity documents reverses two policies the Biden administration rolled out: one that allowed transgender people to change the gender on their passports without providing proof of their transitions, and another that allowed applicants who are intersex or identify as neither male nor female to select an “X” gender marker. This story first appeared on NBCNews.com. More from NBC News: Trump tours fire-ravaged Los Angeles after chiding California and FEMA Chicago school district says it was wrong about ICE agents going to a school Mexico refuses to accept a U.S. deportation flight