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President Obama nominated Mary Jo White to be the next chairwoman of the Securities and Exchange Commission today, tapping a top white-collar crime prosecutor to "keep going after irresponsible behavior" on Wall Street.

"Mary Jo does not intimidate easily," the president said in the State Dining Room of the White House. "And that's important because she has a big job ahead of her. The SEC played a critical role in protecting our financial system during the worst of the financial crisis, but there's much more work to be done to complete the task of reforming Wall Street and making sure that American investors are better informed and better protected going forward."

"I am absolutely confident that Mary Jo has the experience and the resolve to tackle these complex issues and protect the American people in a way that is smart and in a way that is fair," he said.

White, currently a partner at Debevoise & Plimpton, spent over a decade as a U.S. attorney in New York, where she prosecuted white-collar criminals and money launderers. In the early 1990's, she led the prosecution of mob boss John Gotti, the head of the Gambino crime syndicate.

"You don't want to mess with Mary Jo," Obama said.

The president also re-nominated Richard Cordray, a "familiar face," to head the Consumer Financial Protection Bureau. Obama used a recess appointment to install Cordray last year after Republicans in Congress repeatedly blocked his nomination.

"Richard's appointment runs out at the end of the year and he can't stay on the job unless the Senate finally gives him the vote that he deserves. Financial institutions have plenty of lobbyists looking out for their interests. The American people need Richard to keep standing up for them. And there's absolutely no excuse for the Senate to wait any longer to confirm him," Obama said.

Both nominations signal Obama's intent to more strictly regulate Wall Street in his second term, as new reforms go into effect.