The U.S. economy crept up a mere 1.8 percent in the first three months of this year, the Commerce Department said Wednesday, revising down its initial estimate of a 2.4 percent increase in the nation's economic performance. The result was the weakest in two years and calls into question hopes that the 2013 gross domestic product will manage to reach 2 percent.

The revised first-quarter reading reflected weak consumer spending, which accounts for about 70 percent of the nation's economy, and was recalculated lower to 2.6 percent from an initial 3.4 percent.

Despite the weak quarterly performance, it marked an improvement over the 0.4 percent gain in the fourth quarter and consumer spending in the first three months of this year was the strongest in two years.

Analysts had been expecting a stronger result from the Commerce Department's revised figures, partly because of forecasts that show the U.S. economy heading for at least a 2 percent GDP for all of 2013.

"The increase in real GDP in the first quarter primarily reflected positive contributions from [personal consumption expenditures], private inventory investment, and residential fixed investment that were partly offset by negative contributions from federal government spending, state and local government spending, and exports. Imports, which are a subtraction in the calculation of GDP, decreased," the Commerce Department said in a statement.

“The lower consumption estimate provides some indication that the impact from fiscal austerity may have been more than previously thought, and that the economy started the year on weaker footing than previous estimated,” Millan Mulraine, of TD Securities, told the Financial Times.

The department also said first-quarter GDP was revised down because "exports and imports are now estimated to have declined."

While the overall first-quarter performance marks an improvement over the previous three months, corporate profits in the first three months of the year fell sharply. Profits from current production fell $28 billion in the first quarter, in contrast to an increase of $45.4 billion in the fourth quarter.

Bank performance also declined, although only slightly: Domestic profits of financial institutions fell $3.4 billion compared to a $3.5 billion decline in the fourth-quarter.

Despite the downward revision to the first-quarter numbers, analysts put a positive spin on the figures.

"Until we see the monthly breakdown of the new consumption figures tomorrow, it is unclear exactly how these first-quarter revisions will affect our second-quarter GDP growth forecast, which is currently for a gain of between 1.5 percent and 2 percent," said Paul Ashworth, chief U.S. economist for London-based Capital Economics. "But it is possible that the downward revision to the first quarter will require an upward revision to the second quarter."