President Barack Obama and his top allies in Congress groped their way Tuesday towards a hard-fought compromise to ensure final passage of a historic US health care overhaul within weeks.
Obama was to hold evening talks with Democratic leaders of the Senate and House of Representatives as they faced the difficult task of melding their rival versions of the legislation, the president's top domestic priority.
Democratic House Speaker Nancy Pelosi said she was "optimistic" the two sides would bridge the gaps between their bills and agree on what would be the most sweeping overhaul of its kind in four decades.
The discussion, at the dawn of a mid-term election year expected to see Democrats lose seats, was the first in a series aimed at securing final passage by Obama's State of the Union speech in late January or early February.
"There are significant differences. We will be discussing these over the next coming weeks," Democratic House Majority Leader Steny Hoyer said after top House Democrats met behind closed doors ahead of the White House talks.
Pelosi signaled, as she had before, that she would likely accept the Senate's decision to strip out a government-backed "public option" to compete with private insurers -- a necessity to get the 60 votes for passage.
"We will have what we need to hold the insurance companies accountable," promised Pelosi, who steered the measure to passage by a razor-thin margin in November. "And they'll be crying out for a public option one of these days."
The speaker suggested a possible showdown over how to pay for the 10-year, one-trillion dollar plan, which would extend coverage to at least 31 million of the 36 million Americans who currently lack it.
The legislation would shave an estimated 132 billion dollars from the soaring US budget deficit, while aiming to ban abusive health insurance practices and curbing skyrocketing US medical costs.
Another potential obstacle is the House bill's tougher restrictions on federal funds subsidizing abortions: While pro-choice lawmakers denounce the limits, some centrist Democrats say they will withhold support without them.
Republicans remained locked in unyielding opposition to the plan, and Democrats were considering skirting the traditional House-Senate "conference" to forge compromise legislation in order to blunt any delaying tactics.
"We don't know what route we will take," said Pelosi. "We will do what is necessary to pass the bill."
Later, Pelosi and Hoyer were to attend the White House talks in person while Democratic Senate Majority Leader Harry Reid and his deputy, Senator Dick Durbin, were to join by telephone.
Passage would hand Obama and congressional Democrats a huge victory ahead of November elections that, if history is any guide, are likely to result in sizeable Republican gains in Congress.
Democrats say they want final passage before Obama's State of the Union speech, which Pelosi has suggested could slide to early February from its typical late January date.
Democrats have virtually no margin for error: The Senate's Christmas Eve vote rallied exactly the 60 votes needed to pass the bill, and some centrists have said they will oppose any major changes.
The United States is the world's richest nation but the only industrialized democracy that does not provide health care coverage to all of its citizens.
As a nation, the United States spends more than double what Britain, France and Germany do per person on health care.
But it lags behind other countries in life expectancy and infant mortality, according to the Organization for Economic Cooperation and Development (OECD).
The House approved its version of the bill on November 7. The Senate adopted its version December 24.