Image copyright Getty Images Image caption US economic activity has picked up strongly as consumers spend more

The US economy grew at a 3.2% annual rate for the final quarter of 2013, according to the country's Commerce Department.

Many predict that 2014 will produce the strongest growth since the end of the US recession in mid-2009.

Optimism over the health of the world's largest economy led to a further easing of the Federal Reserve's stimulus measures on Wednesday.

The Fed said it would cut monthly bond purchases by $10bn (£6bn) to $65bn.

Its bond-buying programme was designed to inject life into the economy and keep long-term interest rates low.

The US central bank had said this week that growth in economic activity had picked up since December.

It also said that consumer spending had boosted overall growth prospects.

Growth

Bill Blain - chief strategist at investors, Mint Partners, told the BBC that Thursday's numbers were encouraging.

"These figures are as expected and demonstrate that the US economy is recovering, it is strengthening. Many of the problems which were troubling the US economy such as a government slowdown are in the past, and we can think of this now as a sustained growth."

However, Mr Blain said that growth driven by consumer spending could cause pause for thought.

"We have to ask if the consumer boom is to continue, and if it is sustainable" he said.

'Cash-strapped'

"There are a lot of cash-strapped middle class people in America, and if interest rates do go up, we could see consumers struggle as they try and meet those potentially higher rates."

The latest GDP figure is the first of three estimates that will be made by the Commerce Department. For the whole of the 2013 period, the Commerce Department said that the US economy grew by 1.9%. that was far below the 2.8% expansion seen in 2012.

Spending cuts and higher federal taxes were considered to have restricted overall growth in 2013.

The economy grew by 0.8% in the fourth quarter of last year compared with the third quarter.

This figure is in line with economists' expectations.