A federal judge on Wednesday urged the State Department to give a gender neutral passport to a Colorado Navy veteran who does not identify being male or female in a case that's the first of its kind in the United States.

U.S. District Judge R. Brooke Jackson also suggested he might issue an order forcing the government to do so if it does not successfully negotiate a settlement to the legal challenge filed by Dana Zzyym, who was denied a passport for refusing to check "male" or "female" on the application.

Zyyym was born with ambiguous sexual characteristics and raised as a boy but later came to identify as intersex and neither man nor woman.

Government lawyers argued that moving beyond two gender choices for passports would upend officials' ability to verify identities and backgrounds because of its reliance on drivers' licenses and birth certificates issued by states offering only male and female gender options.

Jackson appeared exasperated at times, saying the State Department needs to catch up to a new era in which gender identification is not as clear as it was in the past.

"A lot of things are changing in our world," Jackson said.

The State Department since 2010 has allowed transgender people to change the gender designation on their passports from male to female or vice versa with a doctor's certification.

An Oregon judge last month allowed Jamie Shupe to be legally classified as a nonbinary person, neither male nor female, in a decision believed the first of its kind in the country.

Shupe's lawyer, Lake Parraguey, said Oregon officials are working on a process to allow Shupe to get a driver's license with that designation.

Parraguey said many states have similar, simple processes to change people's gender identities, similar to a name changes, and orders like Shupe's will eventually have to be honored by other states.

The gender on Zzyym's birth certificate originally was left blank although the document was amended to say that gender was unknown.

Zzyym, who lives in Fort Collins, served in the U.S. Navy as a man before identifying as intersex while working and studying at Colorado State University.