Ben Bernanke, the chairman of the Federal Reserve, said on Friday that pulling back on aggressive policy measures too soon would pose a real risk of damaging a still-fragile recovery.

There has been some disagreement within the Fed of whether the U.S. central bank's bond-buying program, which is designed to push down long-term interest rates, should be phased out.

Fed Board Governor Jeremy Stein argued recently there were signs of overheating in certain financial markets and that the central bank should consider using monetary policy to address such risks if they persist.

Editor's Note: Use This Single Loophole to Pay Zero Taxes. See Video

The Fed chief was not convinced, saying that, even for the purposes of financial stability, a continuation of the central bank's aggressive stimulus, conducted through purchases of Treasury and mortgage securities, remains the optimal approach.

"In light of the moderate pace of the recovery and the continued high level of economic slack, dialing back accommodation with the goal of deterring excessive risk-taking in some areas poses its own risks to growth, price stability, and, ultimately, financial stability," Bernanke said in remarks prepared for delivery at a conference sponsored by the Federal Reserve Bank of San Francisco.

In response to the financial crisis and deep recession of 2007-2009, the Fed not only chopped official rates to effectively zero, but also bought more than $2.5 trillion in assets in an effort to keep long-term rates low.

Still, economic growth remains subdued and is expected to register just 2 percent this year, while the jobless rate remains elevated at 7.9 percent currently.

"Premature rate increases would carry a high risk of short-circuiting the recovery, possibly leading - ironically enough - to an even longer period of low long-term rates," Bernanke said.

He noted that a stimulative monetary policy was simply a response to economic conditions, rather than any attempt to keep rates artificially low to inflate asset prices.

Policymakers are cognizant of possible risks to financial stability, he said, while indicating a preference for employing regulatory and supervisory tools to mitigate any possible fallout from the Fed's low-rate policy.

"We pay special attention to developments at the largest, most complex financial firms," Bernanke said.

He argued banks had gone some way toward repairing their balance sheets since the financial crisis. The Federal Deposit Insurance Corp. reported this week that bank profits rose in 2012 to their highest levels since 2006, the year before the subprime mortgage meltdown gained momentum.

Earlier this week, Bernanke delivered a strong defense of the Fed's unconventional monetary policies in testimony before Congress. He also warned lawmakers to avoid the looming short-term spending cuts known as the sequester.