U.S. central bankers debating the merits of raising interest rates last month described the decision as a close call, with several saying a rate hike was needed "relatively soon," minutes of the September meeting showed.

"Several members judged that it would be appropriate to increase the target range for the federal funds rate relatively soon if economic developments unfolded about as the committee expected," the minutes from the Sept. 20-21 gathering in Washington showed. "It was noted that a reasonable argument could be made either for an increase at this meeting or for waiting for some additional information on the labor market and inflation."

The Federal Open Market Committee left the benchmark lending rate unchanged in a range of 0.25% to 0.5% for the sixth straight meeting last month, even as a majority of the 17 participants still forecast at least one hike this year.