U.S. Secretary of State Hillary Clinton said Thursday it was a "great regret" the United States was not yet a signatory to the International Criminal Court (ICC) in The Hague.
The United States signed the ICC treaty when Hillary's husband, Bill Clinton, was president, but it was never ratified by Congress.
Clinton's successor George W. Bush later rejected the idea of joining the court.
"This is a great regret that we are not a signatory," she said at a town hall meeting in Nairobi.
"I think we could have worked out some of the challenges that are raised concerning our membership," Clinton said. "But that has not yet come to pass."
The ICC is the world's first permanent war crimes court.