WASHINGTON (Bloomberg) — President Barack Obama signalled support for a proposal to impose fees on some of the nation's largest financial firms to cover losses from risky transactions and avert another market meltdown.

Obama, at a White House news conference on Tuesday night, said the US may need a mechanism similar to the Federal Deposit Insurance Corp. for firms that engage in "some of these other far-out transactions" that put the financial system at risk.

"So if you guys want to do them, then you've got to put something into the kitty make sure that if you screw up, it's not taxpayer dollars that have to pay for it, but it's dollars coming out of your profits," he said.

The president also said executives at firms that have received government bailout money should "feel a little remorse and feel embarrassed" about taking million-dollar bonuses.

Obama used most of his news conference to urge Congress to act on his plan for a sweeping overhaul of the health-care system and assure the public that it will give them more choices on insurance and cut the cost of medical care.

Obama targeted insurance companies, which the administration has worked with periodically in developing legislation, as he defended his drive to create a government-run plan that would help cover the estimated 46 million uninsured Americans. He said that provision would "keep insurance companies honest".

"At the time when everybody's getting hammered, they're making record profits and premiums are going up," Obama said.

Obama vowed his health plan won't add to the deficit and will provide greater stability for families. He said he was open to ideas for helping pay for the overhaul, including a surtax on the wealthiest Americans, those with family incomes of $1 million or more.

"That meets my principle" that the cost of the health-care overhaul is "not being shouldered by families who are already having a tough time", he said. Obama left open the possibility that some middle-income Americans may have to contribute, saying he would oppose any proposal that is "primarily funded" by taxing that group.

Obama defended his deadline for the House and Senate to pass a bill before leaving in early August for their monthlong summer recess.

"If you don't set deadlines in this town, things don't happen," he said. "The default position is inertia."

Obama is trying to counter an escalating Republican effort to stymie his top domestic agenda and a rebellion by a group of Democrats over the cost of his plan.

House Speaker Nancy Pelosi, a California Democrat, said yesterday she has the votes to pass her chamber's version of health-care legislation. Still, both House and Senate Democratic leaders left open the possibility that the August deadline for a vote may slip.

Obama said he has no second thoughts about the $700 billion federal rescue of financial firms and the auto industry, even though it was unpopular with the public. The financial system has stabilised and banks are showing profits, he said.

The Standard & Poors 500 Index has risen 19 percent since Obama took office. The benchmark index for US equities has rallied 41 percent over the past four months, led by a 95 percent rise in financial firms. Obama said "it's a good thing" that banks are profitable again.

"What we haven't seen, I think, is the kind of change in behaviour and practices on Wall Street that would ensure that we don't find ourselves in a fix again, where we've got to bail out these folks while they're taking huge risks and taking huge bonuses," Obama said.

FDIC Chairman Sheila Bair has proposed creating an industry-supported fund to provide working capital and cover unanticipated losses when the government steps in to unwind a failed firm.

Bair's proposal is aimed at preventing the government from having to bail out or arrange an acquisition for a firm whose failure could disrupt the financial system. In the last two years, the US has rescued, taken over or helped sell Bear Stearns Cos., Merrill Lynch & Co., American International Group Inc., IndyMac Bancorp Inc., Fannie Mae and Freddie Mac.

"That is one of the ideas that is going to be working its way through the process," Obama said. Without constraints, banks "could take even more risks".

Last night marked Obama's fourth prime-time news conference since taking office, along with several others conducted during overseas trips. By comparison, former Presidents George W. Bush and Bill Clinton each held four prime-time news conferences over their eight years in office, according to Martha Joynt Kumar, a professor of political science at Towson University in Towson, Maryland, who tracks such data. Former President Ronald Reagan held 31 over two terms, she said.