St. Louis Federal Reserve Bank President James Bullard said he argued for a deeper rate cut than his colleagues approved earlier this week because he fears that the economy is slowing and manufacturing "already appears in recession."

Separately, Boston Fed President Eric Rosengren also explained his dissent, which came not because he wanted even lower rates but rather because the thought the central bank did not need to adjust rates at all. Rosengren said he worried that pushing rates lower risked inflating asset prices and household debt.

The policymaking Federal Open Market Committee on Wednesday approved a 25 basis point cut that took the target range for the central bank's overnight borrowing rate to 1.75% to 2%.

Bullard said in a note that the committee should have gone further to a 50 basis point reduction. He added that the committee can always go back and hike rates later if the downside risks fail to materialize.

He said that "there are signs that U.S. economic growth is expected to slow in the near horizon. Trade policy uncertainty remains elevated, U.S. manufacturing already appears in recession, and many estimates of recession probabilities have risen from low to moderate levels."

"In my view, lowering the target range by 50 basis points to 1.50%-1.75% would have been a more appropriate action," he wrote.