Federal Reserve Bank of Boston President Eric Rosengren said he wants to continue the central bank’s bond purchases through year’s end and raise or lower the pace in response to economic data.

Fed policy should pursue “faster economic growth and a more rapid improvement in the unemployment rate,” Rosengren said in the text of remarks prepared for delivery in Manchester, New Hampshire. “We should continue our large-scale asset purchases of Treasury and mortgage-backed securities through this year, although the amount may need to be adjusted up or down, depending on how the economic situation evolves.”

Rosengren, who votes on monetary policy this year, has supported the central bank’s monthly purchases of $85 billion in Treasuries and mortgage-backed securities as a means to try to bring down 7.7 percent unemployment. The Fed previously bought $2.3 trillion of assets in two earlier quantitative-easing programs.

Fed Chairman Ben S. Bernanke said last week the central bank would alter monthly buying in response to gains in the job market, underscoring a need for flexibility. He said further gains would be needed to be sure “this is not a temporary improvement.”