US President Barack Obama is to make an "opening argument" on a perennial crusade that has thwarted previous presidents -- making affordable healthcare available to all Americans.
Obama, who made healthcare reform a centerpiece of his election campaign last year, will hold a televised White House "summit" on Thursday, as the first step in a politically perilous plan.
The event at the White House, with 120 lawmakers, officials and healthcare experts comes a week after Obama asked Congress in his budget for 634 billion dollars to fund healthcare reform over the next 10 years.
"This is the first, sort of the opening argument," White House spokesman Robert Gibbs said on Wednesday.
"This is a first step in starting a process that the president believes is long overdue."
The forum will be screened on the C-Span public affairs network and is expected to be streamed live on the Internet, as Obama opens the meeting with remarks before participants break out into several discussion forums.
The format is similar to a fiscal responsibility "summit" Obama held last week, in line with his stated attempt to reach across political divides to trim the gaping US budget deficit.
Obama opened his drive for healthcare reform on Monday by nominating Kansas Governor Kathleen Sebelius as his new health secretary, to replace former senator Tom Daschle who withdrew over a storm over unpaid taxes.
The president argued that relieving families and businesses of the soaring costs of healthcare payments was not just a moral imperative but was key to solving the crisis.
"We cannot fail to act yet again," Obama said, vowing to make good on a campaign promise to offer "quality, affordable healthcare" to every American.
"Fixing what's wrong with our health care system is no longer just a moral imperative, but a fiscal imperative.
"The crushing cost of healthcare causes a bankruptcy in America every 30 seconds, and by the end of this year, it could cause 1.5 million Americans to lose their homes."
The details of Obama's proposals are not yet clear, and efforts to frame legislation have already been launched by Democrats in Congress.
Republicans are expected to try to derail the president's healthcare plan and force a victory that would severely diminish his political clout. Critics of healthcare reform often deride plans to expand coverage as "European-style socialized medicine."
Former president Bill Clinton's failed healthcare reform drive, under the direction of his wife Hillary Clinton, still sends shudders down the spines of leading Democrats.
The United States has one of the world's most advanced, but confusing healthcare systems, a patchwork of private and state coverage, distinct from the single payer national health systems of Canada and Britain for example.
More than half of Americans are covered by health insurance provided by their employers, but such insurance is not a requirement and nearly 46 million Americans have no coverage at all.
The federal government in 2006 covered about a third of US healthcare spending, mainly through its health insurance programs for the poor and elderly -- Medicaid and Medicare.
Payments by private insurances companies accounted for another 34 percent, while out-of-pocket payments by individuals amounted to 14 percent of the total. The remainder came from state and local funds and other private funds.