Federal Reserve Bank of Boston President Eric Rosengren said the Fed should press on with record stimulus to speed economic growth, reduce 7.5 percent unemployment and boost inflation running below 2 percent.

“While we have seen some improvement in labor market conditions, significant accommodation remains appropriate at this time,” Rosengren said in remarks prepared for a speech in Minneapolis.

“Core inflation remains at the very low end of recent experience, and the unemployment rate is close to the cyclical peaks of the past two recessions.”

The Boston Fed chief has been among policy makers warning about inflation, which slowed to 1 percent in March, the lowest since October 2009, as measured by the personal consumption expenditures index. A voter this year on monetary policy, Rosengren echoed testimony last week by Chairman Ben Bernanke, who said “premature tightening” could reduce inflation and jeopardize the economic expansion.

With unemployment lingering at 7.5 percent — still higher than before the last recession — the Federal Open Market Committee announced May 1 that it will increase or decrease the pace of its monthly bond purchases in response to changes in inflation and the labor market.

The policy makers agreed to maintain monthly buying of $40 billion in mortgage securities and $45 billion of U.S. Treasurys in a bid to boost employment. The bond buying has expanded total Fed assets to $3.4 trillion.

‘Dual Mandate’

“If the incoming economic data do not reflect improvements consistent with both elements of our dual mandate, I believe the Fed should be willing to increase asset purchases,” Rosengren said.

Fed officials have left the benchmark lending rate near zero since December 2008.

Reversing the unprecedented accommodation “could lead interest rates to rise temporarily but would also carry a substantial risk of slowing or ending the economic recovery and causing inflation to fall further,” Bernanke said in testimony to the Joint Economic Committee of Congress.

Soaring stock prices, housing gains and improving consumer confidence indicate the expansion may be gaining momentum. The Standard & Poor’s 500 Index has advanced 16.4 percent this year through Tuesday’s close.

The Conference Board’s sentiment index rose to 76.2 in May, exceeding all estimates in a Bloomberg survey of economists and the highest since February 2008, data from the New York-based private research group showed.

Five-Year High

The measure is in line with the Bloomberg Consumer Comfort Index, which climbed to a five-year high in the week ended April 28, and the Thomson Reuters/University of Michigan preliminary consumer sentiment reading that was at its strongest in May since July 2007.

Rising home prices are bolstering household balance sheets and Americans’ spirits. The S&P/Case-Shiller index of property values in 20 cities increased 10.9 percent in the year to March, the biggest 12-month gain since April 2006.

Still, Rosengren has warned that failing to address low inflation could mean the U.S. will follow the path of Japan, where deflation has become “quite difficult to reverse,” he said in May 16 remarks in Milan. Prices lingering below the Fed’s 2 percent target may mean policy “has not been sufficiently accommodative,” he said.

St. Louis Fed President James Bullard said May 23 in London that more disinflation could prompt additional asset purchases by the central bank. Charles Evans, head of the Chicago Fed, said May 9 that inflation is “too low,” though “it’s too early” to respond with a policy shift.

Rosengren, 55, became president of the Boston Fed in July 2007, and previously served in the economic and supervision departments of the bank. The Boston Fed covers Connecticut excluding Fairfield County, Maine, Massachusetts, New Hampshire, Rhode Island and Vermont.