The minutes also revealed a split between the committee members over the timing of future stimulus moves.

US stock markets closed down on the news, with the Dow Jones slipping down 0.38% to 12,604 and the S&P 500 closed flat at 1,341 and the Nasdaq fell 0.49% to 2,887.

Asian markets also fell sharply following the publication of the minutes. The Nikkei 225 fell 1.48% to 8,720 and the Hang Seng Index closed 1.7% down at 19,090.

The minutes published on Wednesday demonstrated concerns that unemployment would remain elevated for another five to six years, but most officials did not see this as reason enough to expand previous efforts to stimulate growth at this time.

A few thought further policy stimulus was immediately necessary, while several others said it might be needed if the US economy lost momentum – if risks to growth deteriorated and if inflation looked set to remain below target.

Officials also expressed concern at the meeting about risks to the US economy stemming from the eurozone debt crisis, the possibility of a “significant slowdown” in China’s economy and the prospect of deep US government-spending cuts and tax increases scheduled to be put into effect at year-end.

Although no imminent action was taken to expand the Fed’s balance sheet, the committee did extend its Operation Twist programme, although several members voiced concerns the move would not be enough to life the US economic recovery from its soft patch.

Paul Edelstein, director of financial economics at HIS Global Insight, said the minutes reveal the Fed is still too optimistic in its outlook.

“Another downgrade is expected later this year or early next year, even if jobs growth strengthens to the 100,000-150,000 range. This will be the trigger for the Fed to initiate another round of bond purchases, which we expect to total roughly $500bn, to include long-term Treasuries and mortgage-backed securities, and to start before or during the first quarter of 2013,” he said.

“Could action come sooner, perhaps at the upcoming July 31-August 1 meeting? We think this is probably too soon, although economic data have been clearly unfavourable since the Fed last met (bad ISM readings and another dismal jobs report). Stay tuned to Bernanke’s Congressional testimony next week for more guidance.”