Washington (CNN) - President Barack Obama said Thursday there were "no winners" in the deal that ended the 16-day government shutdown and averted a possible U.S. default, then challenged Republican conservatives to drop their anti-government ideology and change how business gets done in Washington.

In a tough and somber statement hours after signing legislation passed by Congress to reopen the government, Obama said the standoff "inflicted completely unnecessary damage (to) our economy" by slowing growth and increasing borrowing costs.