The United States' Olympic and Paralympic Committee has effectively barred transgender women from competing in women's sports, telling the federations overseeing swimming, athletics and other sports it has an "obligation to comply" with an executive order issued by US President Donald Trump.

The new policy, announced Monday with a quiet change on the USOPC's website and confirmed in a letter sent to national sport governing bodies, follows a similar step taken by the NCAA earlier this year.

The USOPC change is noted obliquely as a detail under "USOPC Athlete Safety Policy" and references Trump's executive order, "Keeping Men Out of Women's Sports", signed in February. That order, among other things, threatens to "rescind all funds" from organizations that allow transgender athlete participation in women's sports.

US Olympic officials told the national governing bodies they will need to follow suit, adding that "the USOPC has engaged in a series of respectful and constructive conversations with federal officials" since Trump signed the order.

"As a federally chartered organization, we have an obligation to comply with federal expectations," USOPC CEO Sarah Hirshland and president Gene Sykes wrote in a letter. "Our revised policy emphasizes the importance of ensuring fair and safe competition environments for women. All National Governing Bodies are required to update their applicable policies in alignment."

The National Women's Law Center put out a statement condemning the move. "By giving in to the political demands, the USOPC is sacrificing the needs and safety of its own athletes," said the organization's president and CEO, Fatima Goss Graves.

The USOPC oversees around 50 national governing bodies, most of which play a role in everything from the grassroots to elite levels of their sports. That raises the possibility that rules might need to be changed at local sports clubs to retain membership of their respective national governing bodies.

Some of those organizations — for instance, USA Track and Field — have long followed guidelines set by their own world federation. World Athletics is considering changes to its policies that would mostly fall in line with Trump's order.

A USA Swimming spokesman said the federation had been made aware of the change and was consulting with the committee to figure out what adjustments it needs to make. USA Fencing changed its policy effective Aug 1 to allow only "athletes who are of the female sex" in women's competition and opening men's events to "all athletes not eligible for the women's category, including transgender women, transgender men, non-binary and intersex athletes and cisgender male athletes."

Agencies via Xinhua