Inflation is already too high and inconsistent with the Federal Reserve's goal of price stability, said Charles Plosser, the president of the Federal Reserve Bank of Philadelphia.

Speaking to an audience brought together by the Philadelphia Business Journal last week, he said: "we will need to reverse course - the exact timing depends on how the economy evolves, but I anticipate the reversal will need to be started sooner rather than later."

To read the speech, click here