A leading U.S. gay rights group, concerned that Houston voters rejected an equal-rights ordinance, wants to meet with NFL Commissioner Roger Goodell to discuss the league's plans to host 2017 Super Bowl in the city, according to a letter made public on Thursday.

Voters in Houston on Tuesday rejected a measure that would have would banned discrimination based on gender identity and sexual orientation, protections not guaranteed under Texas law.

"We are writing to request an emergency meeting about the urgent need for a nondiscrimination ordinance in this city that will ensure the thousands of employees, contractors and attendees at this event will be fully protected under the law," wrote Human Rights Campaign President Chad Griffin, whose group advocates on behalf of lesbian, gay, bisexual and transgender people.

The National Football League's Super Bowl, one of the most visible sporting events in the world, is set to be played at Houston's NRG Stadium on Feb. 5, 2017.

"Commissioner Goodell, you have emphasized the NFL's commitment to diversity and inclusion, respect and fairness," Griffin said in the letter dated Nov. 4. "Out of that commitment we hope you will work with us to find a path forward in Houston."

"Finding a path to nondiscrimination protections that ensure all Houstonians are treated equally and fairly remains our crucial and urgent mission," he added.

The Houston Equal Rights Ordinance was backed by outgoing Mayor Annise Parker, the first open lesbian to be elected as mayor of a major U.S. city and local business. Prominent Republicans and Christian pastors, however, rallied against the proposal, known as HERO.

The ordinance would ban discrimination in city employment and city services, city contracts, public accommodations, private employment and housing based on criteria including an individual's sexual orientation and gender identity. But critics raised concerns about its potential impact on who could use men's and women's public bathrooms.

"We will work closely with the Houston Super Bowl Host Committee to make sure all fans feel welcomed at our events," the NFL said in a statement.

"Our policies emphasize tolerance and inclusiveness, and prohibit discrimination based on age, gender, race, religion, sexual orientation, or any other improper standard," the league said.