President Barack Obama on Wednesday formally nominated Janet Yellen, "one of the nation's foremost economists," to succeed Ben Bernanke as chief of the U.S. Federal Reserve.

Obama praised Bernanke's work as Fed chief during one of the most complicated economic periods in U.S. history, and he proposed Yellen, the Fed's current deputy chair, as his replacement.

If confirmed by the Senate, Yellen will become the first woman to head the U.S. central bank.

Obama emphasized that Yellen, who for the last decade has held responsible posts within the Fed, was one of the first people to sound the alarm before the 2008 financial crisis and she clearly understands both aspects of the central bank's dual mandate to control inflation and promote employment.

"Janet is exceptionally well qualified for this role," he said at a White House ceremony, with Yellen and Bernanke at his side.

"She doesn't have a crystal ball, but what she does have is a keen understanding about how markets and the economy work, not just in theory but also in the real world. And she calls it like she sees it," Obama said of the nominee.

Yellen, 67, that she would promote full employment, stable prices and a stable financial system in her new post.

"The mandate of the Federal Reserve is to serve all the American people, and too many Americans still can't find a job and worry how they'll pay their bills and provide for their families," she said.

Obama called on the Senate to approve Yellen's nomination "without delay," but there is apparently no significant opposition to her appointment on the Republican side of the aisle. EFE