WASHINGTON – The economy isn’t growing fast enough to lower unemployment and still needs help from the Federal Reserve’s $600 billion Treasury bond-purchase program.

That was the assessment Wednesday of Fed policymakers as they ended their first meeting of the year. The Fed made no changes to the program, and the decision was unanimous.

The conclusion came from a new lineup of voting members that includes two officials who have raised questions about the bond program. They worry that the purchases could eventually ignite inflation or speculative buying in assets like stocks.

The bond-buying program is intended to lower rates on loans and lift stock prices, spurring more spending and invigorating the economy. Chairman Ben Bernanke faces the challenge of trying to increase hiring and growth without creating new economic threats.

The tax-cut package that took effect this month is easing pressure on the Fed to stimulate growth through the bond purchases. The measure renewed income-tax cuts and cut workers’ Social Security taxes.

The Fed’s assessment of the economy was nearly identical to its statement at its last meeting in December. The policymakers seemed to downplay recent improvements in the economy, including stronger spending by consumers and more production at factories.

Instead, the Fed noted that the economy still faces risks. The biggest: that high unemployment will dampen consumer spending, which accounts for 70 percent of economic activity.

One of the Fed’s main reasons for launching the bond-buying program was to lower high unemployment, now at 9.4 percent.

The Fed noted a recent increase in the prices of commodities, such as oil and gasoline, but said it isn’t likely to spark high inflation. The prospect that inflation will remain tame gives the Fed leeway to stick with its program, announced Nov. 3, to buy $600 billion worth of Treasury debt by the end of June.

The Fed kept its pledge to hold a key interest rate at a record low near zero.