The suit, which names Mr. Biden’s health secretary, Xavier Becerra, as its lead defendant, grows out of guidance issued on Monday by the federal Department of Health and Human Services. The agency has instructed hospitals that, even in states where abortion is illegal, federal law requires doctors to perform abortions for pregnant women who show up in their emergency departments if they believe it is “the stabilizing treatment necessary” to resolve an emergency medical condition.

“President Biden is flagrantly disregarding the legislative and democratic process — and flouting the Supreme Court’s ruling before the ink is dry — by having his appointed bureaucrats mandate that hospitals and emergency medicine physicians must perform abortions,” Mr. Paxton wrote in a complaint filed Thursday in the United States District Court in Lubbock, Texas.

White House Press Secretary Karine Jean-Pierre responded in a statement citing “yet another example of an extreme and radical Republican elected official.” Without naming Mr. Paxton, the statement said it was “unthinkable that this public official would sue to block women from receiving life-saving care in emergency rooms, a right protected under U.S. law.”