U.S. economic growth unexpectedly slowed in the fourth quarter as the strongest pace of consumer spending in three years resulted in a surge in imports.

Gross domestic product expanded at a 2.6 percent annual rate also restrained by a modest pace of inventory accumulation, the Commerce Department said in its advance fourth-quarter GDP report on Friday. That followed a 3.2 percent growth pace in the third quarter.

Imports, which subtract from GDP growth, increased at their fastest rate in more than seven years. Rising imports underscore the challenges that the Trump administration faces in its quest to boost annual GDP growth to 3 percent.

A measure of domestic demand jumped at a 4.6 percent rate, the quickest since the third quarter of 2014, highlighting the economy's strength. Final sales to private domestic purchasers rose at a 2.2 percent pace in the third quarter.

Strong domestic demand is part of a synchronized global rebound that includes the euro zone and Asia. Demand has also been buoyed by President Donald Trump's promise of hefty tax cuts, which was fulfilled in December when the Republican-controlled U.S. Congress approved the largest overhaul of the tax code in 30 years.

Economists polled by Reuters had forecast the economy growing at a 3.0 percent pace in the final three months of 2017.

The economy grew 2.3 percent in 2017, an acceleration from the 1.5 percent logged in 2016. Economists expect annual GDP growth will hit the government's 3 percent target this year, spurred in part by a weak dollar, rising oil prices and strengthening global economy.

While the corporate income tax rate has been slashed to 21 percent from 35 percent and taxes for households have also been lowered, economists see only a modest boost to GDP growth as the fiscal stimulus is coming at a time when the economy is almost at full employment.

Prices for U.S. Treasurys pared losses after the data, while the dollar was little changed at lower levels. U.S. stock index futures were trading higher.