“I have no idea whether the president knew,” Mr. McCain, Arizona Republican, said early Sunday on CNN’s “State of the Union.” “The president may not have done it himself, but the president is certainly responsible as the commander in chief.”
Mr. McCain, who lost the 2008 presidential election to Mr. Obama, has been the leading critic of the White House over the national security leaks, which he and other congressional leaders blame on the administration.
Mr. Obama on Friday said that accusation was “offensive.”
“It’s ‘offensive’ what has happened,” he said, and he again rejected the idea that Attorney General Eric H. Holder Jr. should be in charge of an investigation into the leaks.
Mr. McCain said Congress wants to see an outside investigator look into the leaks because the Obama-appointed Mr. Holder has “no credibility.”
The controversy over the security breaches began last week with the publication in the New York Times of a story that included detailed information about covert U.S. cyberattacks on Iranian computers.
The Arizona senator and other leading Republicans have accused administration officials of trying to bolster Mr. Obama’s foreign policy credentials ahead of the November election.
Democrats, including Sens. John F. Kerry of Massachusetts, who chairs the Foreign Affairs Committee, and Dianne Feinstein of California, who chairs the Intelligence Committee, also have condemned the leaks and pledged to lead their own investigations.