Novak, who disclosed Plame's identity in a 2003 column, urged the public and media to ask the president about the source rather than pressing journalists who received the information.
Novak also suggested the administration official who gave him the information is the same person who mentioned Plame and her undercover CIA role to Washington Post Assistant Managing Editor Bob Woodward in the summer of 2003.
"I'm confident the president knows who the source is," Novak told a luncheon audience at the John Locke Foundation in Raleigh, N.C., the Post reported. "I'd be amazed if he doesn't."
Sen. Charles E. Schumer, D-N.Y., sent a letter to Bush Wednesday urging him to name the source of the leak and make public any disciplinary action taken "in keeping with your stated desire to root out leaks."