WASHINGTON — President Obama on Sunday called Hillary Rodham Clinton’s use of a private email server “a mistake,” but said it had not endangered national security and had been “ginned-up” into a political attack by Republicans eager to keep her from being president.

Mr. Obama made the comments during an interview on CBS’s “60 Minutes” program in which he also defended his policy in Syria during a lengthy, contentious exchange with Steve Kroft, a veteran correspondent.

Mrs. Clinton’s use of the email server during her tenure as secretary of state has become the centerpiece of Republican-led investigations into the 2012 attacks in Benghazi, Libya, that killed four Americans. She is certain to face questions about the emails during Tuesday’s Democratic presidential debate and later this month when she is set to appear before a House committee.

In the interview, which was taped Tuesday and broadcast Sunday evening, Mr. Obama called those questions legitimate and said — without directing the comments specifically at Mrs. Clinton — that public officials in high office should know better.