FRANKFURT: The appointment of Janet Yellen as the next U.S. Treasury secretary is good news for the global economy as the former Federal Reserve chair is aware of the global ramifications of her country's policy, the vice president of the European Central Bank said on Wednesday.

"Janet Yellen knows perfectly what the U.S. economy needs and she is perfectly aware of the implications that the economic policy of the United States is going to have on the world economy," Luis de Guindos said at a news conference.

"The appointment of Janet Yellen is good news for the U.S. economy and the global economy."

The ECB has criticised Donald Trump's outgoing administration for its protectionist stance and was attacked by the U.S. president over the euro-dollar exchange rate.