Richard Fisher, president and chief executive officer of the Federal Reserve Bank of Dallas.

A top U.S. Federal Reserve official critical of the U.S. central bank's super-easy monetary policy on Friday questioned the very core of the Fed's current approach, which rests on giving markets a better sense of the future path of interest rates.

That approach, known as forward guidance, received a makeover on Wednesday, when Janet Yellen wrapped her first policy-setting meeting as Fed chair with a decision to jettison narrow economic guideposts in favor of a much broader set of measures to determine the timing and pace of future rate hikes.