Several voting Federal Reserve policymakers judged a rate hike would be warranted "relatively soon" if the US economy continued to strengthen, according to the minutes of the Fed's September policy meeting released.
The minutes of the 20-21 September meeting, at which the US central bank held rates steady, also showed the depth of the divide at the Fed over timing.
"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...expected," the Fed said in the minutes.
Seventeen policymakers participated at the September policy meeting, of whom 10 had a vote.
In the minutes, both voting members and the wider group were divided on how much longer they should allow the labour market and inflation to improve before raising rates.
The minutes also said "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 labour market and inflation."
US stocks rose slightly following the release of the minutes, while yields on US government debt pared earlier gains.
Three voting members of the rate-setting committee dissented in the September policy statement in favour of an immediate hike, the first time since 2011 that so many have taken such action in the same direction at a single meeting.
In that policy statement, the Fed incorporated new phrasing saying it would maintain current interest rate levels for "the time being," widely seen as a hawkish signal.
According to the minutes, however, a few voting members were concerned the inclusion of the phrase "might be misread as indicating that the passage of time rather than the accumulation of evidence" would drive future decision making.
Although Fed policymakers disagree on whether the current 1.7% inflation rate is sufficiently close to their 2% objective, many voting members remarked that "there were few signs of emerging inflationary pressures."
Since the meeting, Chair Janet Yellen and several other Fed policymakers have said they expect a rate hike by year-end should the labour market and inflation continue to strengthen.
New York Fed President William Dudley said earlier the Fed could afford to be "gentle" in raising rates as the US economy has "plenty of room to run".
Almost all agree that after another rate hike, the path of interest rates will be much shallower than the Fed's last tightening cycle.
Last Friday's monthly jobs report for September showed that while employment gains are slowing, they are still well above the level required to offset population growth.
There are two more meetings scheduled this year, on 1-2 November and 13-14 December.
Traders have all but ruled out a move at the meeting that takes place just a week before the US presidential election.
They currently see about a 66% probability the Fed will raise rates in December, according to data from CME Group.
Ms Yellen is scheduled to deliver a speech on Friday in Boston, which may offer insight into the Fed's latest thinking.