A New York City proposal would allow people born there the option to choose a third gender on their city birth certificates.

Democratic Mayor Bill de Blasio and City Council Speaker Corey Johnson said the new category of “X” would be available under the new plan for those who don’t identify as either male or female.

The proposal is expected to be heard on June 5 at a meeting of the Board of Health. Another hearing will be held in July and then a vote in September, if approved by the board.

Current laws allow parents, who don’t wish to identify the gender of a newborn, to designate their child’s sex as undermined or unknown. The new “X” category would be something adults could choose for their own birth certificate.

Other states across the U.S. have a third gender option in their birth certificates, including California, Oregon and Washington. In Washington, D.C., a third gender option is available on drivers’ licenses.

De Blasio and Johnson said the new proposal is in the spirit of Lesbian, Gay, Bisexual and Transgender Pride Month that spans throughout June.

"Pride Month is a time to celebrate how far we've come in the fight for equality, and re-affirm our commitment to protecting all New Yorkers from discrimination," the New York mayor said. "This proposal will allow transgender and gender non-conforming New Yorkers to live with the dignity and respect they deserve, and make our City fairer."

Johnson, a Democrat, introduced legislation in 2014 that removed a requirement for a person looking to change his or her gender designation on a birth certificate to have undergone sex reassignment surgery.

But even after that, the process still required a medical or mental health professional to fill out an affidavit or affirmation saying the applicant's gender identity was more accurately reflected by changing the gender designation.

"This proposal will allow transgender and gender non-conforming New Yorkers to live with the dignity and respect they deserve, and make our City fairer." — NYC Mayor Bill de Blasio

The legislation being introduced this week also would remove that requirement, and allow people filing for the change to submit their own affidavit saying it was to affirm their gender identity.

The Associated Press contributed to this report.