President Donald Trump said on Monday other countries had provided great reports on the effectiveness of malaria drug hydroxychloroquine for treatment of the deadly coronavirus.
He complained that only U.S. agencies have failed to grasp its benefit.
His remarks, delivered to reporters at the White House, came hours after the U.S. Food and Drug Administration revoked its emergency use authorization for hydroxychloroquine to treat COVID-19.
This came following some disappointing results from studies of the drug's efficacy, though some of those studies have themselves come under fire.
The FDA ruling also came despite Trump's frequent praise of the drug's usefulness for staving off the disease.