Boston Federal Reserve Bank President Eric Rosengren, who dissented from the central bank's decision to cut interest rates earlier this week, repeated on Friday that monetary stimulus was not needed for the U.S. economy and posed its own problems.

"Additional monetary stimulus is not needed for an economy where labor markets are already tight, and risks further inflating the prices of risky assets and encouraging households and firms to take on too much leverage," Rosengren said in a statement explaining his decision.

"While risks clearly exist related to trade and geopolitical concerns, lowering rates to address uncertainty is not costless," he added.

On Wednesday the Fed voted 7-3 to cut borrowing costs by a quarter of a percentage point to a range of 1.75% to 2.00% after a similar cut in July in what Fed Chair Powell has termed a "mid-cycle adjustment" to maintain a record U.S. economic expansion.

Robust consumer spending, low unemployment and some other recent economic data suggest the U.S. economy is still growing moderately but a number of Fed officials have grown concerned about the impact of slowing global growth and a year-long U.S.-China trade war, particularly on the manufacturing sector.

Rosengren and Kansas City Federal Reserve President Esther George have dissented from both interest rate cuts this year, while St. Louis Fed President James Bullard wanted to lower borrowing costs by half a percentage point at this week's policy meeting. He cited signs that U.S. manufacturing already appeared in recession.