The chairman of the Federal Reserve, Ben Bernanke, has signalled that the US central bank will not take any immediate action to boost growth. In a keenly anticipated speech, Mr Bernanke simply said the Fed had a range of tools that could be used to provide additional monetary stimulus.
The Fed's September meeting would last for two days instead of one, he added.
Earlier, revised data showed the US economy grew less than first estimated in the second quarter of 2011.
The Commerce Department now says the economy expanded at an annualised rate of 1% between April and March, down from its first estimate of 1.3%.
The figures were seen as raising pressure on the Federal Reserve to do more to boost the economy, for instance by introducing further quantitative easing - an injection of cash into the financial system.
Mr Bernanke said the central bank's next meeting in September had been extended to allow a fuller discussion of its next move.
The Committee will continue to assess the economic outlook in light of incoming information and is prepared to employ its tools as appropriate to promote a stronger economic recovery in a context of price stability, he said.
Speaking at a meeting of central bankers in Jackson Hole, Wyoming, Mr Bernanke hinted that the US government needed to do more to aid growth.
Most of the economic policies that support robust economic growth in the long run are outside the province of the central bank, he said.
To achieve economic and financial stability, US fiscal policy must be placed on a sustainable path that ensures that debt relative to national income is at least stable or, preferably, declining over time.
As I have emphasised on previous occasions, without significant policy changes, the finances of the federal government will inevitably spiral out of control, risking severe economic and financial damage.
This view was supported by Vincent Reinhart, a former director of the Federal Reserve Board's Division of Monetary Affairs.
Federal Reserve officials would like nothing more than to be left alone: the basic problem is that if you drew up a list of what could be done out of Washington to try to help economic expansion, Federal Reserve action is pretty low on the list.
The reason why we have this unhealthy focus on the Federal Reserve is that the politicians aren't delivering things that could be more effective, he told the BBC.
The Federal Reserve had already said that it plans to keep US interest rates at the current low level of between zero and 0.25% until the middle of 2013.
Earlier in the week, world stock markets had risen as investors speculated that the central bank may pave the way for a third round of quantitative easing, dubbed QE3. But they have been in retreat since Thursday when opinion moved towards the speech not revealing plans for any new measures.
They dipped further immediately after the speech but later recovered and were trading roughly flat.
The earlier data from the Commerce Department reiterated the low rate of growth the US is experiencing, as consumer spending remains weak in the face of high unemployment and higher energy bills.
Bernanke admitted that the pace of the recovery in the US had proved disappointing thus far. But he added that he expected growth in the second half of the year to pick up as temporary factors, including the increase in commodity prices and the Japanese earthquake and tsunami, begin to have less of an impact.