By Michael S. Derby 

Federal Reserve officials sparred Friday over whether the central bank is likely to move too soon or wait too long to raise interest rates.

The presidents of the Minneapolis and Philadelphia regional Fed banks both dissented for different reasons at the central bank's policy meeting Wednesday, at which it signaled it is likely to start lifting rates from near zero next year.

The Fed said in a statement after the meeting it could "be patient" in deciding when to start raising rates. Fed Chairwoman Janet Yellen, in a news conference after the meeting, said that means the Fed likely won't move until after its next two meetings, in January and March.

Minneapolis Fed President Narayana Kocherlakota suggested Friday that the central bank is preparing to move too fast, saying in a statement that its plans could cause inflation and expectations of inflation to sink lower. Inflation has been running below the Fed's 2% target for more than two years.

Mr. Kocherlakota, who will step down in 2016 when his term ends, said the Fed should commit to keeping interest rates very low until the one-to-two-year expected inflation outlook is seen moving back toward its target.

The Fed's "failure to respond to weak inflation runs the risk of creating a harmful downward slide in inflation and longer-term inflation expectations of the kind that we have seen in Japan and Europe," he said.

Meanwhile, Philadelphia Fed leader Charles Plosser renewed his criticism that the Fed may be behind the curve on raising rates, saying in a statement that "waiting too long to initiate a gradual increase in rates could result in the need for more aggressive policy in the future, which could lead to unnecessary volatility and instability."

Mr. Plosser, who has said he will step down in early 2015, said he dissented over the pledge to "be patient" because it implies the decision will be based on a time period rather than on the evolution of the economy. "I am afraid the [Fed] is not leaving itself the flexibility to respond to the data if we continue to see an improving economy," he said.

Mr. Kocherlakota has been one of the strongest supporters of aggressive Fed action to help spur the economy. Other officials sympathetic to that view have slowly moved toward embracing the idea of raising rates next year.

San Francisco Fed President John Williams, speaking Friday on Bloomberg Radio, said the U.S. economy is in "a very good place right now," and that next June "seems a reasonable starting point for thinking about liftoff" of interest rates.

He said he expects inflation to be soft next year but continues to believe a recovering job market and sustained growth will push price increases back up to the desired level over time.

Mr. Williams, who gains a vote on the Fed's policy-setting committee in 2015, said the central bank will likely have to look through weak price gains next year, saying that so-called core inflation--which excludes volatile food and energy prices--"will likely be below 2% when liftoff is appropriate." He said if inflation doesn't appear likely to rise, the Fed can either delay rate increases or move more slowly with the overall pace of boosting borrowing costs.

Consumer prices, by the Fed's preferred measure, were up 1.4% in October from a year before and are forecast to weaken further in the months ahead due to falling oil prices.