The US Senate voted to advance a historic, trillion-dollar infrastructure package late Wednesday, a breakthrough after weeks of often-bitter negotiations on a bill that President Joe Biden said could "transform America."

The deal, if passed by Congress and signed into law, would pump historic levels of federal funding into fixing US roads, bridges and waterways, ensuring broadband internet for all Americans and expanding clean energy programs.

The bipartisan measure passed 67-32, with 17 Republicans joining all 50 Democrats to formally begin debate on the bill.  

The plan, part of Biden's sweeping domestic agenda, includes some $550 billion in new spending. It came together despite a near collapse of the volatile talks, which Biden and his Democrats wanted to see concluded before Congress breaks for its August recess.

The legislation's language has yet to be written, but because the bill itself is just a shell, the Senate can advance it before voting on the final text.

That scenario caused Republicans to balk at beginning debate last week, and some are still warning it could sink the plan.

'Do big things'

"Until this bill is actually written, and we have a chance to review it, including all the details, the costs, the pay-fors... I will not support it," Senator John Cornyn said on the Senate floor.

"And I imagine the majority of my Republican colleagues will feel the same way."

The deal will create millions of good jobs and make the US economy more robust, sustainable, resilient and just, the White House said in a statement.

Biden called it "the most significant long-term investment in our infrastructure and competitiveness in nearly a century."

"This deal signals to the world that our democracy can function, deliver, and do big things," he said, adding that the plan had the potential to "transform America and propel us into the future."

The deal will make the largest-ever federal investments in public transit and drinking and waste water infrastructure; the largest funding of passenger rail since the creation of Amtrak; and the largest investment in bridges since creation of the nation's highway system.

It also helps tackle the climate crisis by investing in clean energy projects such as electrification of school and transit buses, and forming an authority to oversee creation of a clean electricity grid.

The bipartisan group negotiating the blueprint overcame a key sticking point: how to pay for the spending.

The White House said revenue would come from redirecting unspent Covid emergency relief funds, boosting corporate fees and strengthening tax enforcement on cryptocurrencies.

'Loser for the USA'

The bill would still need to clear the House of Representatives, where it could face resistance from progressive Democrats.

Some have warned they would not sign on unless Biden's ambitious $3.5 trillion budget package -- including once-in-a-generation spending on health care, education, social welfare and climate action -- also passes the Senate.

That package, which Democrats plan to pass without Republican support through a budget reconciliation process, is proceeding on track and is expected to get a floor vote before the Senate breaks for its recess, Senate Majority Leader Chuck Schumer said.

"It might take some long nights. It might eat into our weekends. But we are going to get the job done," Schumer said.

Former president Donald Trump pushed back strongly against the bipartisan bill, saying in a statement the deal is "a loser for the USA, a terrible deal, and makes the Republicans look weak, foolish, and dumb."

The agreement was announced shortly after Biden traveled a Pennsylvania truck factory where he called on Congress to pass tougher "Buy American" policies that would boost the US-made content in $600 billion of government purchases.

Biden said his administration was proposing legislation to update the 1933 Buy American Act to close loopholes and pressure businesses that provide items to the government to add more US-made inputs to their supply chains.

"I can sum it up in two words: 'Buy American,'" Biden told about 130 employees and others at the Mack Trucks Lehigh Valley Operations Manufacturing Facility.