The U.S. Federal Reserve will likely completely wind down its bond-buying program by the fourth quarter unless the economy takes a serious turn for the worse, a top official at the central bank said on Wednesday.

Dennis Lockhart, president of the Federal Reserve Bank of Atlanta, said he expects the U.S. economy to grow as much as 3 percent this year and that it was too early to know if a spate of weak data signaled fundamental troubles or the temporary effects of a particularly cold winter.

The Fed in January began winding down a massive bond-buying stimulus program, and Lockhart said it would take a lot to make the central bank change course.

"As long as the outlook remains solid and does not deviate dramatically from the path we believe it's on, I would expect the tapering of asset purchases to continue over the balance of the year," he said in prepared remarks at Mercer University.

"I expect the asset purchase program to be completely wound down by the fourth quarter of this year."