The US Food and Drug Administration filed an appeal on Friday against a ruling by a federal judge that overturned the approval of a safe and effective abortion pill, court records showed.
A federal judge in the US state of Texas overturned the two-decade-old approval of the pill, the latest volley in a conservative battle against reproductive rights in the United States.
The FDA's notice of appeal was filed on Friday in Texas and signed by lawyers representing the agency, according to court documents.
"The FDA has appealed this decision. FDA approved Mifeprex more than 20 years ago based on a comprehensive review of the scientific evidence available and determined that it was safe and effective for its indicated use - medical termination of early pregnancy," the FDA said in a statement to US media.
If it stands, the ruling by an appointee of former US president Donald Trump would reverse permission granted by the FDA for mifepristone, a drug widely used for over two decades to terminate unwanted pregnancies.
President Joe Biden announced on Friday that the Department of Justice had also filed an appeal, pledging to "fight this ruling".
"The lawsuit, and this ruling, is another unprecedented step in taking away basic freedoms from women and putting their health at risk," he said in a statement.
Moments after the Texas decision on Friday, a judge in Washington state ruled in a separate case that access to the drug must be preserved in more than a dozen states.
In an illustration of how deep the fracture on abortion runs in US society, the dueling legal opinions mean the issue is almost certain to end up before the Supreme Court.
The conservative-dominated panel last year overturned the landmark Roe v Wade ruling that had enshrined a woman's right to abortion for half a century.