St. Louis Federal Reserve Bank President James Bullard said he was not aware of any warning that the Swiss bank gave to the Fed ahead of its move to lift the cap, which sent the Swiss franc soaring and led to huge foreign exchange losses across the globe.

"The Swiss economy is just too small to have an impact," Bullard said, in a session with reporters here after a speech he gave to the CFA Society.

Bullard said that events have gone against the Swiss National Bank, as Europe's economy has weakened and the European Central Bank is nearing a decision to launch a major bond-buying program, which puts tremendous pressure on the euro/Swiss franc exchange rate.

"I don’t want to Monday morning quarterback these guys. But if you want to learn a lesson from it, I think it's got to be that if you're going to undertake a policy like that you also have to have a careful reasoning about under what conditions you expect to remove your policy," Bullard told reporters.

(Reporting by Tom Polansek in Chicago and Michael Flaherty in Washington; Editing by Meredith Mazzilli)