Federal Reserve Chairman Jerome Powell says the outlook for the US economy is "extraordinarily uncertain" and the success of the recovery effort will depend in large part on the country's ability to contain the spread of the coronavirus. "A full recovery is unlikely until people are confident that it is safe to re-engage in a broad range of activities," Powell says in testimony he is scheduled to deliver on Tuesday in an appearance with Treasury Secretary Steven Mnuchin before the House Financial Services Committee. In the testimony released on Monday by the Fed, Powell repeats a pledge that the central bank will keep interest rates at their current ultra-low levels until it is sure the economy has weathered the pandemic crisis. His comments come as parts of the country are experiencing a surge in coronavirus cases that have prompted governors to backtrack some of their steps to reopen their states' economies.