The Federal Reserve's leading inflation hawk told CNBC that interest rates will have to rise soon in order to keep a lid on rising prices.
"We need to take steps to ensure that inflation does not get out of control," Philadelphia Fed President Charles Plosser said in a live interview. "It is certainly clear that rates will have to rise. The question is when." (See full interview in videos below)
Plosser comments are the latest in a series of speeches by Fed officials about the dangers of inflation, though the messages have been somewhat mixed.
On Wednesday, Fed Vice Chairman Donald Kohn hinted that the central bank is inclined to leave rates steadydespite rising inflation worries among US consumers.
Kohn said that when the economy is hit with an oil price shock as it has been this year, the "appropriate" Fed policy will permit -- temporarily -- both higher inflation and higher unemployment.
And on Monday, Fed Chairman Ben Bernanke said the central bank would work to restrain consumer expectationsof higher prices, hinting that the Fed may be inclined to boost rates if inflation worsens.
The Fed is hoping tough talk on inflation will do the job of moderating recent price increases, giving it room to avoid raising interest rates as the economy remains fragile.
Plosser, however, stressed that the Fed may need to act soon against inflation.
"We can't control the price of oil directly, but we can control the underlying inflation pressures for the economy," he said.
Plosser also said he and his central bank colleagues must work to lessen the effects of the crisis in the financial system as well as inflation.
"I think they're both real threats, and I think we have to manage both of them," he said.
Plosser said the Fed has taken aggressive steps to counter both problems, but he urged continued vigilance, saying the base of inflation is broadening, and the Fed is in a unique position to act.
Plosser feels the Fed mishandled inflation in the 1970s by acting too late, allowing a relative price shock in oil to translate into higher inflation.
Plosser endorsed Fed efforts to tackle the credit crunch -- such as opening the discount window -- with some reservations.
"I think the Fed has been very creative and aggressive in trying to contain the crisis in the financial markets and the turmoil, and we've done some very interesting, innovative things," he said. "Those decisions and choices we've made have cost some benefits. They contain some risk and challenges."
He also expressed reservations about government efforts to stimulate the economy through tax-rebate checks.
"I am not counting on that having substantial impact on the economy going forward," he said.