The Federal Reserve should remain on track to raise interest rates later this year despite the U.S. economy’s weak start to the year and a stock market sell-off this week, two Fed officials said on Thursday. In separate events in Frankfurt and Detroit, St. Louis Fed President James Bullard and Atlanta Fed President Dennis Lockhart said U.S. monetary policy might need to be adjusted in light of the economy’s steady improvement since the 2007-2009 financial crisis. Fed policymakers also lowered their growth forecasts at last week’s policy-setting meeting.