WASHINGTON – Federal Reserve Chairman Ben Bernanke met with senators Wednesday to defend his expansion of record monetary stimulus, saying it would aid job growth and the central bank would control inflation.

Bernanke said that he and his colleagues “remain absolutely committed to not letting inflation or inflationary expectations get out of control,” Sen. Evan Bayh, D-Ind., told reporters after the 40-minute closed-door session on Capitol Hill.

The Fed chief told senators that central bank officials “want to do what they can now to encourage more growth rather than less,” Bayh said. The second round of purchases follows a $1.7 trillion program.

Sen. Richard Shelby, R-Ala. and the senior Republican on the Banking Committee, said Bernanke cited an estimate that the program may help create 700,000 to 1 million jobs. Bernanke met with 11 committee members amid a Republican backlash against the Nov. 3 decision by central bankers to buy an additional $600 billion of Treasury debt.

Also Wednesday, the four top Republicans in Congress wrote to Bernanke expressing “deep concerns” over the central bank’s second round of Treasury bond purchases. The action may introduce “significant uncertainty” on the dollar’s strength while generating “hard-to-control, long-term inflation” and asset bubbles, the letter from Senate Republican Leader Mitch McConnell and three other lawmakers said.

Sen. Mike Johanns, R-Neb., said of the Fed’s purchases that he thinks the “effect of what they are trying to do has at best a marginal impact.”

Johanns said he told Bernanke that the Fed runs the risk of putting too much cash into markets, which will fuel commodity prices and create “boom-and-bust” cycles. The result of Fed action could be “over-inflating parts of the economy,” Johanns said.

Bernanke repeated his view that the central bank needs help from Congress in aiding the economy. “He went out of his way to say that he absolutely hopes Congress will take the lead in setting economic policy,” Bayh said.