US airlines to add more gender options

US airlines will add more gender options for passengers who don't identify as "male" or "female", the media reported on Tuesday.

The Airlines for America (A4A), the industry trade group, and members of the International Air Transport Association recently approved a new international standard for non-binary passengers effective from June 1, CNN reported.

The new gender options to be added include "unspecified" and "undisclosed".

"US airlines value a culture of diversity and inclusion, both in the workplace and for our passengers, and we work hard each day to accommodate the needs of all travellers, while delivering a safe, secure and enjoyable flight experience," A4A said in a statement on Monday.

Implementation of the new gender options is up to each individual carrier, according to A4A.

Alaska Airlines, American Airlines, Hawaiian Airlines, JetBlue, Southwest and United are all members of the industry body.

American Airlines confirmed to CNN that they were working to implement the change to accommodate passengers.

"In the coming weeks, customers will be able to select the gender with which they most closely identify during the booking process," United Airlines tweeted.

The National Centre for Transgender Equality (NCTE) hailed the decision, saying that it "applauds the A4A for adding gender options that are reflective of the diversity of their passengers".

"Non-binary people face unnecessary, invasive, and discriminatory scrutiny by airlines, airports, and security services alike... (It) is an important step toward ensuring safe and smooth travel for all passengers regardless of their gender," NCTE spokesperson Arli Christian said.

The development came as many US states were adding more gender options on identification cards and birth certificates.

Last month, a new law in New York city made it easier for transgender and non-binary residents to match their birth certificate to their gender identity without needing a signed affidavit from a healthcare provider.

In 2017, Washington, D.C. issued the nation's first gender-neutral driver's licenses.