By Ann Saphir and Lindsay Dunsmuir (Reuters) -The U.S. central bank must move “expeditiously” to bring too-high inflation to heel, Federal Reserve Chair Jerome Powell said on Monday, and will, if needed, use bigger-than-usual interest rate hikes to do so. “The labor market is very strong, and inflation is much too high,” Powell told a National Association for Business Economics conference. “There is an obvious need to move expeditiously to return the stance of monetary policy to a more neutral level, and then to move to more restrictive levels if that is what is required to restore price stabi…