U.S. stocks were set to fall at the open on Wednesday ahead of a highly anticipated statement and news conference by the Federal Reserve later in the session, with the Fed expected to give clearer clues on how soon it plans to tighten monetary policy. The U.S. central bank is expected to provide indications on the timing of its first interest rate hike in nearly a decade, as it assesses whether the U.S. economic recovery can hold up against collapsing oil prices and a soaring dollar. A Fed statement is due at 2:00 p.m.