U.S. President Barack Obama, accompanied by Vice-President Joe Biden, hails the passing of the health-care reform bill in the Senate. (Charles Dharapak/Associated Press)

The U.S. Senate passed landmark health-care reform legislation on Thursday, a nearly $1-trillion bill pledging to extend coverage to an estimated 30 million Americans.

The bill still needs to go through the process of reconciliation in which legislation passed in the House of Representatives is harmonized with the Senate's bill. Negotiations could extend until at least February.

U.S. President Barack Obama hailed the vote for bringing the country "toward the end of a nearly century-long struggle to reform America's health-care system."

"With passage of reform bills in both the House and the Senate, we are now finally poised to deliver on the promise of real meaningful health insurance reform that will bring additional security and stability to the American people," he said Thursday morning.

Obama said that if the bill is passed, it will be the most important piece of social legislation since the Social Security Act passed in the 1930s.

The final Senate vote, which passed by 60-39 on strict party lines, needed only a simple majority to pass. This follows three procedural votes that passed this week, which needed a 60-vote win. Democrats have needed all 58 members and two Independents to pass those legislative hurdles against unanimous Republican opposition and a threatened filibuster.

Thursday morning's vote was the Senate's first Christmas Eve vote since 1895, when the issue was a military affairs bill concerning employment of former Confederate officers, according to the Senate Historical Office.

There are major differences between the House and Senate bills, including stricter abortion language in the House bill, a new government-run insurance option in the House bill that's missing from the Senate version, and a tax on high-value insurance plans in the Senate that is strongly opposed by many House Democrats.

Fragile support

Some Democratic senators have warned that the Senate bill is supported by a fragile coalition, and that any major change would threaten its survival.

A number of concessions were made to get the 60 senators on board, including the removal of the so-called public health insurance option and of a measure to lower the age for Medicare eligibility. While centrist Democratic senators had opposed those provisions, their removal has upset many liberal Democrats.

The proposed bills, each estimated to cost around $1 trillion US over 10 years, would be paid for by a combination of tax and fee increases and cuts in projected Medicare spending, which includes cuts to insurance companies, doctors and hospitals.

The bills would ban insurance companies from denying coverage for those with pre-existing conditions. The legislation would also for the first time make health insurance mandatory for nearly everyone in the U.S., provide subsidies to help low-income people buy it, and induce employers to provide it with tax breaks for small businesses and penalties for larger ones.

The non-partisan Congressional Budget Office has estimated that the Senate bill would cut the U.S. national deficit by $132 billion over the next 10 years.

But Republican critics say that reduction is predicated on a $500-billion cut to Medicare, something that may prove difficult.

Critics have also blasted the legislation, arguing it will raise health-care costs and insurance premiums. They argue new legislation will lead to the rationing of health care and hurt quality of overall care.

House minority leader John Boehner slammed the bill moments after passage.

"Not even Ebenezer Scrooge himself could devise a scheme as cruel and greedy as Democrats' government takeover of health care," the Ohio Republican said in a statement.

"[The] health-care bill increases premiums for families and small businesses, raises taxes during a recession, cuts seniors' Medicare benefits, adds to our skyrocketing debt, and puts bureaucrats in charge of decisions that should be made by patients and doctors," he said.

With files from The Associated Press