US Treasury yields fell sharply on Wednesday because the US Federal Reserve projected interest rates to remain close to zero till 2023.The Fed also said it would maintain the pace of asset purchases for now--$40 bln of US Treasury notes and $80 bln agency-backed mortgage security loans per month.Yield on the 10-year US Treasury note ended at 0.75% on Wednesday as against 0.84% on Tuesday.The US central bank did not rule out the use of yield curve control to cap yields of long-term securities. Fed Chairman Jerome Powell said its effectiveness was still an open question and a decision would be made after a better understanding of the economy's trajectory.The policy measure had been a point of discussion among market participants given the steepness in the US Treasury yield curve. Some market participants expect the US central bank to resort to the measure in a few months.The economic projections led some market participants to believe, materially, economic recovery would take a long time.While leaving the federal funds rate target ranged unchanged at 0.00-0.25%, Powell said the US central bank was not even thinking about raising interest rates and its focus was more on targeting the unemployment rate. Unemployment rate in May was at 13.3%.