The US Senate is poised for a vote to advance a bipartisan gun control bill that supporters hope will help curb the mass shootings that have rocked the country, in what could be Congress’s first new limits on guns in decades.

The 80-page Bipartisan Safer Communities Act would encourage states to keep guns out of the hands of those deemed to be dangerous and tighten background checks for would-be gun purchasers convicted of domestic violence or significant crimes as juveniles.

It does not include more sweeping gun control measure favoured by Democrats including President Joe Biden, such as a ban on assault-style rifles or high-capacity magazines.

Mr Biden renewed calls for action following a pair of high-profile shootings in Buffalo, New York, and Uvalde, Texas.

The legislation will need support from 60 of the Senate’s 100 lawmakers to overcome Thursday’s procedural hurdle.

With the chamber split 50-50, it will need the support of at least 10 Republicans to advance.

Democrats were optimistic after 14 Republicans supported an initial step forward on Tuesday.

“Sixty four members came together … to move forward, an unmistakable sign of the broad support and momentum behind this bill,” Democratic Majority Leader Chuck Schumer said in a floor speech on Wednesday.

If Thursday’s vote succeeds, the bill would come up for a vote on passage that is expected no later than Friday.

Republicans who back the bill insist that it does not erode the rights of law-abiding gun owners, are among their most ardent constituents.

“It does not so much as touch the rights of the overwhelming majority of American gun owners, who are law-abiding citizens of sound mind,” said Senate Republican leader Mitch McConnell, who backs the legislation.

But Republican supporters have faced criticism over the legislation, which is opposed by the National Rifle Association, the nation’s biggest gun lobby.

The bill provides funding to help states adopt “red flag” laws to keep firearms out of the hands of those deemed a danger to themselves or others.

It would also fund alternative intervention measures in states where red flag laws are opposed and provide for enhanced school security.

It closes the “boyfriend loophole” by denying gun purchases to those convicted of abusing intimate partners in dating relationships, and allows states to add juvenile criminal and mental health records to national background check databases.

Senator John Cornyn, the lead Republican negotiator on the bill, was booed last week as he discussed its contents during a speech before a Republican Party convention in his home state of Texas.

Senator Richard Durbin, the chamber’s No.2 Democrat, said the bill would provide $US4.5 billion in funding to Justice Department, Department of Health and Human Services and the Department of Education.

A Republican aide estimated the measure’s overall price tag at $US15 billion.