The U.S. economy expanded at a 2.9 percent pace last year, the Commerce Department reported Thursday, a strong rate but just shy of President Donald Trump's goal of 3 percent.

Last year's growth marked the fastest gain for the economy since 2015. The economy received a big boost from the largest corporate tax cut in U.S. history that went into effect last year, as well as additional government spending on the military and domestic programs. But that stimulus is widely expected to wear off later this year, causing growth to slow somewhat in 2019.

Growth in the final quarter of last year was 2.6 percent, above forecasts but below the 3.4 percent pace in the third quarter and 4.2 percent pace in the second quarter.

Trump and his top officials have repeatedly said they can achieve at least 3 percent annual growth for the next decade, but the vast majority of economists predict growth will be lower this year. The Federal Reserve is currently predicting 2.3 percent growth for 2019.

"Last year was likely the best year of this business cycle," said Ellen Zentner, chief economist at Morgan Stanley. "We stimulated the heck out of the economy last year and that stimulus will fade this year."

The Commerce Department had to delay this report because of the partial government shutdown that furloughed many employees who work on key economic data collection and calculation.