President Obama concluded a day of partisan clashes at the White House's made-for-TV health care summit by vowing to pass the overhaul with or without Republicans, signaling his willingness to force the bill through Congress using controversial tactics.
Mr. Obama asked Republicans for support on passing his stalled top agenda item, but spoke bleakly of overcoming significant policy differences at the end of the bipartisan event.
"I don't know, frankly, whether we can close that gap," Mr. Obama said. "If we can't close that gap, I suspect [congressional leaders of both parties] are going to have a lot of arguments about procedures in Congress about moving forward."
Republicans didn't seem to think anything in Mr. Obama's revision of the Democrats' plan would lead to real changes.
"I just don't think the president was listening," Senate Minority Whip Jon Kyl, Arizona Republican, said after the meeting.
The administration touted the summit as a chance to revive health care reform - which has passed both the House and Senate but not the important conference between the two chambers - among lawmakers skittish about the plan and a public that has grown frustrated with the messy and partisan yearlong debate.
The summit was intended to counter two chief complaints Mr. Obama faced in the health care debate: that he wasn't listening to Republican ideas and that he wasn't airing negotiations on C-SPAN, in violation of a campaign pledge. The event was broadcast on C-SPAN, and Republicans talked about their ideas.
In sometimes heated exchanges, Republicans picked apart the reform bills and criticized Democrats for refusing their call to start the debate from scratch, with an emphasis on small-scales fixes such as medical malpractice reform.
"Our view, with all respect, is this is a car that can't be recalled and fixed and we ought to start over," said Sen. Lamar Alexander, Tennessee Republican.
Mr. Obama and congressional Democrats argued that the national health care system is so broken that a sweeping bill is the only way to stem the rising costs.
"An incremental approach is like a swimmer who's 50 feet off shore drowning, and you throw him a 10-foot rope," said Sen. Tom Harkin, Iowa Democrat and chairman of the Health, Education, Labor and Pensions Committee. "And you say, 'Well, it didn't reach him, but we'll get it back and we'll throw him a 20-foot rope next time.' "
By the end of the day, Mr. Obama said he would work with Republicans on two of their top issues - allowing health insurers to sell across state lines and reforming medical malpractice laws. But he and congressional Democrats said the Republicans' other plans - including a proposal to establish high-risk insurance pools - wouldn't do enough to cover the 46 million uninsured Americans.
The Congressional Budget Office found that the Republican plan would cover about 3 million of the uninsured. Democrats argued that it wasn't enough and that their plan would extend coverage to about 31 million.
Part of the proposal from House Republicans would allow people with pricey health care bills and labeled "high risk" to be able to buy coverage in a pool, with the goal of lowering premium rates by spreading the risk among more people.
Democrats included the pools in their plan as well, but only as a stopgap until they can set up insurance exchanges that would allow Americans to buy private coverage. Democrats argue that it's not a long-term solution because the insurance pools would draw only sick or elderly people who cannot afford other plans, driving up premium rates.
The prospect of compromise was dim at the end of the seven-hour summit. Mr. Obama had expressed hope that it would be a serious negotiating session, but it often devolved into a series of campaign-style speeches that mirrored party talking points.
House Speaker Nancy Pelosi, California Democrat, told reporters at the White House after the summit that she's not optimistic that Republicans would vote for the bill. But Democrats pledged to move forward.
"It's time to do something and we're going to do it," said Senate Majority Leader Harry Reid, Nevada Democrat.
Democrats have suggested that they would pursue reconciliation - the complicated procedural tool that circumvents the chance for a Republican filibuster in the Senate - if they can't get support from Republicans, who remain uniformly opposed to the Democrats' plans.
Mr. Obama's health care reform effort stalled on Capitol Hill shortly after Democrats lost their 60th, filibuster-breaking vote in the Senate with the special election win in Massachusetts of Scott Brown, who campaigned strongly against the bill.
In an only-in-Washington debate, lawmakers quarreled several times about how the Congressional Budget Office - Congress' nonpartisan budget keeper - scored and analyzed the parties' legislation.
Mr. Alexander accused the Democrats' Senate bill of raising premiums for people in the individual health care market, which drew sharp rebuke from Mr. Obama.
"No, no, no, no," he said. "Let me - and this is an example of where we've got to get our facts straight."
The CBO ruled that the cost to families in the individual market - those who have to buy coverage on their own directly from an insurer - would in fact be 10 percent to 13 percent higher under the Senate plan. But the customer would get government subsidies to help defray the cost, which would decrease their cost.
• Kara Rowland contributed to this report.