WASHINGTON — Fed policy makers have become slightly more optimistic about the pace of the economic recovery, but they continue to predict that unemployment will remain well above 9 percent through the end of 2010, according to forecasts released on Tuesday.

The new forecasts, released along with minutes from the central bank’s policy meeting earlier this month, showed that officials remained cautious about the strength of the economic recovery but have begun a more intensive debate about when to start raising short-term interest rates.

According to the minutes, some policy makers worried that holding short-term interest rates at almost zero could encourage “excessive risk-taking” and expectations of higher inflation.

“Members noted the possibility that some negative side effects might result from the maintenance of very low short-term interest rates,” the central bank reported in its summary of the meeting. Though policy makers decided the risks were “relatively low,” the Fed said, they agreed to “remain alert.”

The minutes provided new light on the debate between the Fed’s more hawkish policy makers, who have argued that inflation pressures may be more imminent than they appear, and an apparent majority of the policy-setting committee that is still worried primarily about high unemployment and the fragility of the recovery.

The new forecasts, produced by each Fed governor in Washington and the presidents of regional Fed banks around the country, were slightly more optimistic about the pace of growth.

The “central tendency” of the Fed forecasts anticipated that the economy would expand 2.5 percent to 3.5 percent next year. That was slightly faster than officials had predicted in June, and it reflected a pick-up in growth this summer that was somewhat faster than Fed officials had expected.

But over all, Fed officials barely budged from their previously somber prognosis of plodding growth, high unemployment and low inflation for the next two years.

“Most members projected that over the next couple of years, the unemployment rate would remain quite elevated and the level of inflation would remain below rates consistent over the longer run with the Federal Reserve’s objectives,” the central bank reported.

For practical purposes, Fed officials have generally wanted to keep the “core” rate of inflation, which excludes volatile prices for food and energy, around 2 percent or slightly below.

But the core rate of inflation has drifted below 1.5 percent over the last year, and most Fed policy makers predicted that it would remain below 2 percent through 2012 and for the longer run as well. To many Fed officials, that means that there is still ample time to keep interest rates low without stoking inflation pressures.