Federal Reserve Chair Janet Yellen said Tuesday that the economic recovery is not yet complete and for that reason the Fed intends to keep providing significant support to boost growth and improve labor market conditions. In delivering the Fed's semi-annual economic report to Congress, Yellen said the Fed's future actions will depend on how well the economy performs. She says if labor market conditions continue to improve more quickly than anticipated, the Fed could raise its key short-term interest rate sooner than currently projected. But she said weaker conditions will mean a longer period of low rates.