Federal Reserve Chairman Ben Bernanke on Friday defended the U.S. central bank’s bond-buying against beggar-thy-neighbor criticism, saying it was “critical” for global stability that the U.S. economy regain its strength.

Doing so, he suggested, would bolster a dollar whose weakness has sparked cries of foul from Bogota to Beijing.

The U.S. central bank’s decision to buy $600 billion of government debt has drawn scathing comments from a host of nations who contend it is generating global instability by ramping up their currencies against the dollar, inflating asset bubbles and stoking inflation in their economies.

“With all due respect, U.S. policy is clueless,” German Finance Minister Wolfgang Schaeuble said in Berlin.

Bernanke, answering questions from college students, stressed that Fed policies aimed at giving a boost to the weak U.S. recovery would pay dividends around the world.

“I think it’s important to emphasize … that a strong U.S. economy, a recovering economy, is critical, not just for Americans but it’s also critical for the global recovery,” Bernanke said.

The Fed’s easy monetary policy, ramped up on Wednesday with the new bond-buying plan, has rankled, especially among emerging market economies and it looks set to be a bone of contention at a G20 summit in Seoul next week.

South African Finance Minister Pravin Gordhan said Fed policy “undermines the spirit of multilateral cooperation” that the G20 had sought to achieve. The money will find its way into financial markets of emerging nations with potentially devastating impact on their exports, he charged.

Bernanke said U.S. policymakers were fully aware of the dollar’s importance in the global economy as a reserve currency. The dollar has weakened sharply and did so again after this week’s decision on a new round of so-called quantitative easing.

“The best fundamentals for the dollar will come when the economy is growing strongly,” Bernanke said. “That’s where the fundamentals come from.”

He told the students that while commodity prices have risen sharply, they were the exception amid generally muted prices for other products and should not cause a serious problem.

Bernanke said there was ample slack in the U.S. economy that will prevent producers from being able to fully price costlier commodities into finished products that consumers buy.

He added that once inflation pressures become visible, the U.S. central bank will be ready to modify its current stance of accommodative monetary policy to block inflation. Official interest rates have been near zero for nearly two years.

For the moment, inflation expectations appear to be quite low, Bernanke said, adding the Fed was committed to keeping them that way and expressing confidence it had the tools to do so.