Despite a lackluster August jobs report, the U.S. central bank will probably reduce its bond-buying program from the current $85 billion per month, given the progress the economy has made over the last year.

Global financial markets were jolted in May when Fed Chairman Ben Bernanke raised the prospect of ratcheting down the Fed's economic stimulus. As U.S. Treasury yields rose, investors sold assets in India and other developing economies that drew inflows in the U.S. easy-money era, prompting complaints by emerging market leaders at last week's Group of 20 meeting.

Stocks have since recovered, although emerging markets could face a fresh bout of pain: European Central Bank Executive Board member Joerg Asmussen warned the spillover from a Fed exit now could be greater now than in 1994, when Fed tightening sparked an emerging market rout.

With the day of reckoning likely upon them, Fed officials may seek to temper the impact of a cut in their purchases by re-emphasizing that buying will continue well into 2014 and that overnight interest rates will not be raised any time soon.

The Fed will update economic forecasts at the conclusion of its September 17-18 meeting and Bernanke will hold a news conference to discuss the policy decision. Hanging over the already-tense meeting is the prospect that President Barack Obama could name Bernanke's successor in coming weeks, which could call into question any longer-term policy promises.

"Given all the energy that has been expended gearing the markets up for a taper, it's hard to imagine the Fed would not take the opportunity to at least cut back modestly this month," said Credit Suisse economist Dana Saporta, who expects a $15 billion to $20 billion reduction.