"It's important that the countries concerned understand this as a wake-up call to tackle their problems head on," he was quoted as saying in a pre-publication copy of an article in business daily Handelsblatt due to be printed on Wednesday.

But he added that there were considerable differences between economies: "You should not tar emerging markets with the same brush."

On Tuesday, hopes for strong policy action in leading developing nations eased an emerging markets rout triggered last week after a currency meltdown in Argentina.

(Reporting by Michelle Martin; Editing by Ruth Pitchford)