A top campaign adviser to President Obama made clear Sunday that the president has no plans to chip in extra money from his own income to defray the deficit — and would insist that the tax system itself be changed so that the wealthy pay more.

Campaign strategist David Axelrod was asked on “Fox News Sunday” whether the president might contribute more to the U.S. Treasury after the release of his tax returns showed Obama paid a lower effective tax rate than his secretary. The president and first lady Michelle Obama paid an effective rate of 20.5 percent on gross income of $789,674, a lower rate than the president’s secretary — who earned less than $100,000.