Federal Reserve officials remarked on the strength of the U.S. economy at a closed-door meeting last month while fretting that markets reflected growing fears of a slowdown on the part of traders.

"In assessing the economic outlook, participants noted the contrast between the strength of incoming data on economic activity and the concerns about downside risks evident in financial markets and in reports from business contacts," according to minutes of the meeting released on Wednesday, Jan. 9.

The central bank, led by Chairman Jerome Powell, voted at the Dec. 18-19 meeting in Washington to raise interest rates to a range between 2.25% and 2.5%.

Fed officials have been raising rates since late 2015 to keep inflation from spiking as the economy accelerated, though in recent months Powell has drawn criticism from President Donald Trump for raising rates too quickly, unnecessarily hampering his efforts to create jobs and drive up the stock market.