WASHINGTON (AP) ― Federal Reserve policymakers are open to further efforts to stimulate the U.S. economy if growth falters or threats escalate.

Minutes of the central bank’s April 24-25 meeting released Wednesday stated that “several members” thought additional Fed support could be needed if the recovery lost momentum or if the risks to the economy became great enough.

The minutes did not spell out what circumstances would trigger further Fed efforts to lower interest rates to boost the economy. But they did note some threats to the U.S. economy. One is Europe’s debt crisis. Another is the risk that spending cuts and tax increases that could take effect at year’s end if Congress can’t reach a budget agreement could slow growth more than expected.

The comments stood in contrast to the previous minutes, which said that only “a couple” of members expressed support for further bond purchases. Since the financial crisis, the Fed has pursued two rounds of bond purchases to try to push down long-term interest rates, with a goal of encouraging borrowing and spending.

Private economists said the change in wording to “several” from “a couple” raised the possibility of further Fed action. But analysts said they still think no further moves will occur unless Europe’s crisis worsens or a budget impasse in Congress threatens the U.S. economy.

“Nothing in the minutes changes our view on policy,” said Sal Guatieri, senior economist at BMO Capital Markets.

The stock market barely reacted to the Fed minutes, which essentially confirmed investors’ expectations for the Fed’s future moves.

On Wednesday, the Fed also announced that for the rest of this year and next year all of its meetings will last for two days to allow more time for discussion. Until now, some policy meetings had lasted only one day.

The Fed also altered the schedule for releasing a quarterly update of its economic forecasts. That release will occur when the Fed meets in the third month of each quarter: March, June, September and December. After those meetings, Bernanke will discuss the Fed’s new outlook with reporters.

Before the change, those forecasts and Bernanke’s news conferences occurred in January, April, June and October. Bernanke started holding regular news conferences a year ago.

The minutes released Wednesday cover the discussion that took place at the April meeting. In a statement after that meeting, Fed officials repeated their plan to keep a key short-term interest rate at a record low until at least late 2014. The action was approved on a 9-1 vote.

Jeffrey Lacker, president of the Federal Reserve Bank of Richmond, opposed retaining the late-2014 target date. The minutes said Lacker believed the Fed will have to start increasing interest rates by mid-2013 in order to keep inflation under control.

At a news conference after April’s meeting, Chairman Ben Bernanke left open the possibility of further Fed action to stimulate the economy. Private economists generally say another round of Fed bond buying isn’t likely unless the economic outlook darkens considerably.

Bernanke said at his news conference that more bond purchases, or other steps by the Fed, were still an option if the economy weakens. He declared that “those tools remain very much on the table.”

Critics have expressed concerns that the central bank was raising the risk of higher inflation with its long-running campaign to keep rates low.

The Fed has kept its federal funds rate, the target for overnight bank lending, near zero since December 2008. That means consumer and business loans tied to that rate have also remained at super-low levels. The lower those loan rates, the more likely it is that consumers and companies will borrow and spend to invigorate the economy.