With the U.S. workforce nearly fully employed and inflation heading toward 2 percent, the Federal Reserve should raise interest rates two more times this year and continue work on a plan to gradually trim its massive balance sheet, Dallas Federal Reserve Bank President Robert Kaplan said."I think we are moving toward a period where we should begin allowing the balance sheet to gradually and patiently run off," said Kaplan, a voter this year on the Fed's policy-setting panel, in an interview with Reuters late Tuesday. "But I think we have work to do, probably, to get to that point."By "work to do," Kaplan was referring to further interest-rate hikes. Kaplan supported last week's interest-rate increase, only the Fed's third since the financial crisis, and said Tuesday the "country will be well-served" by the decision.