The Federal Reserve chairman Ben Bernanke says the US economic recovery will rebound in the coming months.
Speaking to a banking conference in Atlanta, he acknowledged that growth had been slower than expected this year but said momentum would build in the second half of the year.
He did not suggest the central bank was planning any further monetary easing.
The latest economic news from the US showed employment growth slowed sharply in May.
Investors had been expecting 150,000 new jobs to have been created last month, instead growth was just a third of that number.
The jobs report was the latest of a string of weak economic releases.
Mr Bernanke said the main reasons hindering growth were external, such as high energy prices and the Japan crises and that the impact of these problems should recede to allow stronger growth before the end of the year.
He said: “Overall, the economic recovery appears to be continuing at a moderate pace, albeit at a rate that is both uneven across sectors and frustratingly slow from the perspective of millions of unemployed and underemployed workers.”
Some investors had been hoping there would be a hint that the Federal Reserve might consider taking further steps to pump money into the economy.
Its $600bn (£366bn) Treasury bond-buying programme, which was designed to help keep interest rates low and money flowing, is ending this month.
Mr Bernanke did say that the economy still needed the benefit of low interest rates.