The US economy grew at an annualised rate of 2% in the July-to-September period, an acceleration on the previous quarter, official figures have shown.
The expansion came despite continuing high unemployment and weakness in the housing market.
The 2% figure is an improvement on the upwardly revised 1.7% increase between April and June, but less than the 3.7% growth recorded from January to March.
The Federal Reserve suggested last week it would do more to boost the economy.
To do this, the Fed - the US central bank - is expected to announce next month that it will resume quantitative easing - injecting fresh money into the economy through the purchase of government bonds.
Compared with the preceding quarter, the US economy grew by 0.5% between July and September.
The economy is continuing to experience a slow recovery by historical standards, with the unemployment rate at 9.6% and Americans increasingly nervous about the future.
This is expected to manifest itself in big losses for President Barack Obama's Democratic Party in Tuesday's congressional elections, which are being seen as a vote on his economic performance.
The Commerce Department's figures showed that businesses building up their inventories - stocks of goods and materials - contributed most of the US economic expansion during the third quarter.
The growth in business inventories made up more than two-thirds of the 2% annualised expansion in the economy.
However, consumer spending also increased, despite continuing high US unemployment.
Consumer spending rose 2.6% during the third quarter, up from 2.2% in the second.
"[Economic] growth is still positive, but a bit disappointing," said Scott Brown, chief economist at Raymond James & Associates.
"It's not where we would like it to be at this point of the recovery."