In this file photo US Federal Reserve Chairman Jerome Powell gives a press briefing in Washington,DC. (Photo: AFP)

US Federal Reserve Chair Jerome Powell on Tuesday pledged that the US central bank will keep benchmark lending rates low until the economy is at full employment and inflation has risen consistently.

Powell repeated his assurance that the Fed will keep rates at the current level near zero until the economy reaches "maximum employment and inflation has risen to 2 percent and is on track to moderately exceed 2 percent for some time."

In the first day of his semi-annual testimony before Congress, Powell said it will take time for the recovery to reach that point, but that Covid-19 vaccines offer hope for a speedy return to normal.