A Federal Reserve policy maker set the stage Thursday for the type of monetary stimulus the nation’s central bankers will consider to help boost the still-struggling U.S. economy.

However, Federal Reserve Bank of St. Louis President James Bullard emphasized that the decision isn’t a done deal, and that the Fed’s policy-setting committee will wait until all available economic data come in before its highly anticipated meeting in early November.

The widely held view among investors is that the Federal Open Market Committee will introduce a second round of quantitative easing, which is expected to involve Fed purchases of U.S. Treasurys.

Bullard suggested that the FOMC announce Treasury purchases in “small increments,” similar to the way the Fed typically raises or lowers the short-term federal-funds rate by a quarter percentage point, or 25 basis points.

The St. Louis Fed chief envisions Fed purchases of $100 billion to start, with further Treasurys buys contingent on the evaluation of economy at future FOMC meetings. The FOMC would have the flexibility to pause or increase the Fed’s Treasurys purchases depending on economic conditions, Bullard said.

Last Friday, Federal Reserve Chairman Ben Bernanke said the Fed is ready to provide additional support, “contingent on incoming information about the economic outlook and financial conditions.”

Recent statements from the Fed indicated that jobless rate is too high and inflation is too low to achieve the Fed’s mandated goals of maximum employment and price stability.

Bullard’s colleague, Chicago Federal Reserve Bank President Charles Evans, supports a policy to lift the Fed’s informal inflation target high enough to create job growth. Evans warned that the U.S. is caught in a “liquidity trap,” as the near-zero federal-funds rate policy is ineffective to grapple with anemic consumer spending and near-completed re-stocking of inventories.

Evans’ proposal is controversial, particularly for those who are known as inflation hawks, such as Bullard. He said he has concerns about Evans’ idea, saying the Fed’s future inflation-fighting credibility is at stake.

Bullard is a voting member this year of the FOMC, while Evans doesn’t currently have a vote.

Bullard made his comments to reporters Thursday at the St. Louis Fed’s annual economic-policy conference.