Treasury Secretary Timothy Geithner, left, with Federal Reserve Chairman Ben Bernanke at right, gestures while testifying Tuesday on Capitol Hill in Washington before a House Financial Services Committee hearing on AIG.

Washington ? Pointing with dismay to the AIG debacle, the nation’s top economic officials argued Tuesday for unprecedented powers to regulate and even take over financial goliaths whose collapse could imperil the entire economy. President Barack Obama agreed and said he hoped “it doesn’t take too long to convince Congress.”

Treasury Secretary Timothy Geithner and Federal Reserve Chairman Ben Bernanke, in a rare joint appearance before a House committee, said the messy federal intervention into American International Group, an insurance giant, demonstrated a need to regulate complex nonbank financial institutions just as banks are now regulated by the Federal Deposit Insurance Corp.

“AIG highlights broad failures of our financial system,” Geithner told the House Financial Services Committee. “We must ensure that our country never faces this situation again.”

Geithner suggested his Treasury Department’s powers be expanded. Bernanke was noncommittal, even suggesting the FDIC.

Both officials sought to channel the widespread public outrage over the millions of dollars AIG spent in post-bailout bonuses into support for regulatory overhaul.

Dealings between Congress and Geithner have been tense at best. But they were a little more relaxed in the afterglow of Monday’s nearly 500-point surge in the Dow Jones industrials, though the Dow gave back about 116 points on Tuesday. The rise came in large part in response to the administration’s unveiling of a public-private program to buy up to $1 trillion in bad loans and toxic mortgage-related securities clogging bank balance sheets.

Geithner is expected to lay out more details on the administration’s plan Thursday when he appears again before the committee. Democrats in the Senate say the administration wants the proposal on taking over non-banks to move separately from the larger financial industry regulatory bill, to get it going more quickly.

At the White House, Obama told reporters, “We are already hard at work in putting forward a detailed proposal. We will work in consultation with members of Congress. That will be just one phase of a broader regulatory framework that we’re going to have to put in place to prevent these kinds of crises from happening again.”

The government has given AIG over $180 billion in bailout funds since it first intervened last Sept. 16. The U.S. now owns nearly 80 percent of the giant insurer.