The US economy contracted at an annual rate of 0.7 percent in the first quarter of this year, the Commerce Department said Friday in a revised GDP estimate.
The downturn was due in part to the impact on trade of the three-month West Coast ports slowdown, as well as a lower level of private inventory investment than previously estimated.
The sharp revision of the original estimate of an 0.2 percent expansion had been expected, as more detailed data on economic output and trade in the January-March period has trickled out in recent weeks.
The impact of the long labor dispute that led to the November-February port slowdown was clear. Overall, trade had a negative 1.9 percent impact on gross domestic product.
Exports fell 7.6 percent in the quarter, after growing 4.5 percent the previous period. Meanwhile, imports rose 5.6 percent, just over half the pace of the previous quarter.
But analysts also say the strengthening dollar is taking a toll on US competitiveness, contributing to the fall in exports.
Other drivers of growth were also weak: personal consumption, business investment, and government spending.
On the bright side, spending on houses and business equipment improved in the quarter. And inventory investment, though not as high as originally thought, was also up from the previous quarter.
Nevertheless, coming after a 2.2 percent rate of expansion in the fourth quarter of 2014, the second winter quarter stall in two years has underpinned continued doubts over the overall strength of the US economy.
Early data of the current period since April is better, however, economists noted, giving hope for a firm rebound.
"This was not a good picture of the US economy but it is all history," said Jennifer Lee of BMO Capital Markets.
"We are more than halfway through Q2 and we are seeing signs that the economy is recovering from the weak first quarter."