Private economists generally agree that a default on the U.S. debt would be extremely harmful, especially if the impasse was not resolved quickly.
"If they don't pay on the debt, that would cost us for generations to come," said Mark Zandi, chief economist at Moody's Analytics. He said a debt default would be a "cataclysmic" event that would roil financial markets in the United States and around the world.
Zandi said that holders of U.S. Treasury bonds would demand higher interest rates which would cost the country hundreds of billions of dollars in higher interest payments in coming years on the national debt.
Boehner and Schumer were interviewed on ABC's "This Week," and Lew and Cruz on CNN's "State of the Union." Lew also appeared on CBS' "Face the Nation," ''Fox News Sunday" and NBC's "Meet the Press."
Associated Press writers Martin Crutsinger and Jim Kuhnhenn contributed to this report.