U.S. Federal Reserve policymakers were worried last month about inflation, but for two opposing reasons.

One group of Federal Reserve policymakers felt inflation was falling too low and argued for caution in raising interest rates. Others expressed concerns that delaying further rate hikes could push inflation higher into dangerous territory.

The policy debate was revealed in minutes released Wednesday of the Fed’s July 25-26 meeting. Officials eventually made a unanimous decision to keep its key policy rate unchanged.

The minutes also showed that several officials pushed for a July announcement that the Fed was ready to start reducing its massive bond holdings, a move that would likely mean slightly higher rates on mortgages and some other loans. Policymakers decided in the end to signal that it would come “relatively soon.”

Financial markets expect that announcement at next month’s meeting, but analysts do not expect the Fed’s next rate hike to come until December. If inflation does not start moving higher again, they say it is likely the Fed will keep rates unchanged until next year.

At the July meeting, officials voted to keep the Fed’s benchmark rate unchanged in a range of 1% to 1.25%. The Fed had raised rates at its March and June meetings even though inflation this year has slowed and is now further from the Fed’s 2% goal than it was at the start of the year. In June, the Fed continued to signal that it expected to raise rates one more time this year.

In their July discussion, the minutes showed that some officials expressed concern about the recent decline in inflation, even though unemployment has continued to decline. It is currently at a 16-year low of 4.3%.

Officials worried about low inflation said that the Fed should delay any further rate hikes until it had greater assurance that the slowdown stemmed from temporary factors and that prices would climb more quickly in coming months.

But other officials worried that with the labour market already at full employment, waiting too long to raise rates again ran the risk of overshooting on the 2% inflation target. That would be “costly to reverse,” meaning that the Fed would have to raise rates more quickly and higher in the future, actions that could push the economy into a recession.

The inflation debate explored a number of issues, the minutes showed, including the possibility that long-held views on the relationship between tight labour markets and higher inflation may no longer be valid.

The Fed’s next meeting is Sept. 19-20.

In an interview Monday with the Associated Press, William Dudley, head of the Fed’s New York regional bank, said that the market’s view that the announcement about bond reductions would come in September was “reasonable.”

Dudley said he did not expect much of an impact on financial markets because the action had been well-telegraphed by the Fed, unlike the “taper tantrum” incident that occurred in 2013 when bond rates temporarily spiked when markets were caught by surprise by comments from then-Fed Chairman Ben Bernanke that the Fed was contemplating moves to reduce the size of its monthly purchases of bonds.

The Fed’s balance sheet has soared five-fold — to US$4.5 trillion — since the summer of 2008, just before the financial crisis erupted. The increase came as a result of purchases the Fed made of Treasury bonds and mortgage-backed securities. The purchases were designed to put downward pressure on long-term interest rates as a way of giving the economy an extra boost after the Fed had cut its short-term rate to a record low near zero.