In the largest gain since 2003, the U.S. economy grew 5.7 percent in the final quarter of 2009.

The U.S. Commerce Department says this is the strongest evidence yet the recession officially ended last year.

The growth was driven largely by a rebound in manufacturing and increases in consumer spending and commercial investments.

However, it will likely be temporary as businesses finish restocking their inventories and the government stimulus wears off.

"Wow, great number. It's very solid and gives us a running start into the second half of the year when we can't rely on government stimulus," Jack Ablin, chief investment officer at Harris Private Bank in Chicago, told ABC News.

"That's part of the plan, to get us moving as fast as possible so when life support is removed we'll have a pulse," he said.

Still, analysts predict the country's gross domestic product will slow to 2.5 for 2010.