(Reuters) -Federal Reserve Governor Christopher Waller on Thursday stepped up his call for cutting short-term U.S. borrowing costs, saying he would support an interest-rate cut next month and further reductions over the next three to six months to prevent the labor market from collapsing.

"Based on what I know today, I would support a 25 basis point cut" at the upcoming September 16-17 meeting of the rate-setting Federal Open Market Committee, he said in remarks prepared for delivery to the Economic Club of Miami.

"While there are signs of a weakening labor market, I worry that conditions could deteriorate further and quite rapidly, and I think it is important that the FOMC not wait until such a deterioration is under way and risk falling behind the curve in setting appropriate monetary policy." 

Waller said he did not think a bigger-than-usual interest-rate cut next month would be needed, though he said that view could change if the Labor Department's August jobs report, due out next Friday, points to a substantially weakening economy, and inflation remains well-contained. 

However, he said "the time has come to ease monetary policy and move it to a more neutral stance," which he defined, based on Fed policymaker estimates, as 1.25 to 1.50 percent points below the current policy rate range of 4.25%-4.50%.

"I don't believe that policy has fallen substantially behind the curve, but one way to signal that I don't intend to allow that happen is to talk about where we go after September," he said. "As I stand here today, I anticipate additional cuts over the next three to six months, and the pace of rate cuts will be driven by the incoming data."

Waller and Fed Governor Michelle Bowman both dissented on July 30 from the Fed's decision to keep short-term borrowing costs unchanged, citing their worries about the labor market weakening.

Both were appointed by U.S. President Donald Trump and are said to be under consideration as possible successors to Fed Chair Jerome Powell, whom Trump has been publicly pressuring to lower interest rates dramatically.

In another move widely seen as part of an effort to exert more control over the Fed, Trump earlier this week announced he was firing Fed Governor Lisa Cook over what he said was possible mortgage fraud, a move Cook says is illegal and is suing to stop.

The Fed did lower the policy rate by a full percentage point last year, starting in September before Trump was elected and continuing after he was elected. It has held rates steady this year, citing worries that Trump's higher tariffs could reignite inflation that is still running above the Fed's 2% goal.

Powell last week appeared sympathetic to some of Waller's reasoning, noting a sharp downturn in job growth to a monthly average of just 35,000 since May, even while the unemployment rate remains a low 4.2%.

Rising downside labor market risks, Powell said, may warrant "proceeding carefully" with a policy adjustment. Analysts and financial markets took those remarks as a strong indication that the Fed would cut rates in September and proceed gradually from there.

Waller on Tuesday cited analysis by Fed staff showing that, apart from the temporary effect of tariffs, inflation is running close to the Fed's 2% goal. That, along with well-anchored longer-term inflation expectations and rising chances of an undesirable weakening in the labor market, means he feels even more strongly than in July that the Fed should be cutting rates now.