The National Collegiate Athletic Association has quickly reversed its policy on allowing transgender student-athletes to play on female teams less than 24 hours after President Trump signed an executive order that made good on his campaign pledge to “keep men out of women’s sports.”

Officials for the governing body overseeing collegiate-level sports announced the change in their policy Thursday after a vote from their Board of Governors on revising their “Participation Policy for Transgender Student-Athletes.”

“We strongly believe that clear, consistent, and uniform eligibility standards would best serve today’s student-athletes instead of a patchwork of conflicting state laws and court decisions,” NCAA President Charlie Baker said in a statement. “To that end, President Trump’s order provides a clear, national standard.”

The updated policy now limits competitive collegiate women’s sports to “student-athletes assigned female at birth.”

Schools will still have the autonomy to determine who they allow to participate, but if any of their women’s teams has an athlete who transitioned, they will no longer be eligible for NCAA women’s championships under the policy.

Mr. Trump signed his latest executive order on Wednesday at an open event at the White House. The order, titled “Keeping Men Out of Women’s Sports,” mandates that Title IX, a federal law that bans schools from sex discrimination, should be interpreted as also prohibiting men who identify as women from participating in female sports.

“The war on women’s sports is over,” Mr. Trump declared as applause erupted from the crowd of young female athletes in attendance.

Schools or other organizations that fail to comply with the new order could jeopardize federal funding.

“We’re putting every school receiving taxpayer dollars on notice,” Mr. Trump said.

Mr. Trump’s order will also affect visa policies for athletes who travel to America to compete in the Olympics, which will take place in Los Angeles in 2028, or other sporting events.

On his first day back at the White House, Mr. Trump called for the federal government to define sex as only male or female and said that policy should be reflected on official documents like passports and in policies like federal prison assignments.

Mr. Trump’s pledge to “keep men out of women’s sports” resonated across party lines. A survey by AP VoteCast found that over half the voters surveyed felt support for transgender rights in government and society in recent years had gone too far.