Washington: President Barack Obama knew that Hillary Rodham Clinton conducted business on a nongovernment email account while secretary of state, but only recently learned the details of the privately run system she was operating, the White House said.

The White House has drawn scrutiny over Clinton's exclusive use of private email and whether Obama or his aides should have done more to ensure her correspondence was secure and properly preserved. In a weekend interview, Obama told CBS News that it was only recently "through news reports" that he'd learned that Clinton was using a nongovernment email system.