PRESIDENT Barack Obama will launch the most sweeping effort to curb US gun violence in nearly two decades, as New York politicians easily passed the toughest gun control law in the country.
The moves follow calls by gun control advocates for swift action after a massacre at an elementary school last month.
The state of New York on Tuesday approved legislation to curb the sale of assault weapons and ammunition, as victims of gun violence joined other protesters at a Walmart parking lot in Connecticut to demand that the retailer stop selling guns similar to the type used by a man who killed 20 children in nearby Newtown.
The Democratic-controlled Assembly in Albany, the capital of New York state, approved the bill after the Republican-majority Senate passed it on Monday, making New York the first state to take legislative action against gun violence since the Newtown massacre.
Among other measures, the bill will crack down on ammunition sales and broaden the definition of assault weapons in New York to make it harder to legally possess them.
Mr Obama will urge a reluctant Congress to ban military-style assault weapons and high-capacity ammunition magazines like those used in the Newtown massacre.
The broad package that Mr Obama will announce is also expected to include more than a dozen steps the President can take on his own through executive action. Those measures will provide a path for skirting opposing politicians, but they will be limited in scope.
But Congress would have to approve the bans on assault weapons and ammunition magazines holding more than 10 bullets, along with a requirement for universal background checks on gun buyers.
Some gun-control advocates worry that opposition from Republicans and conservative Democrats, as well as the National Rifle Association, will be too great to overcome.
For many Americans, gun ownership is a cherished right protected by the Second Amendment of the US constitution. Others argue that the country's founders in the 18th century could never have envisioned the sort of high-powered assault weapons used in the Newtown attack.
Support for banning high-capacity magazines has reached a new high, at 65 per cent, according to an ABC News/Washington Post poll released early this week. The survey has tracked the issue since early 2011.
A requirement of background checks on firearms buyers at gun shows has the support of 88 per cent of Americans, while 58 per cent want to ban the sale of assault weapons, the poll found.
Fifty-five per cent back the NRA's call for armed guards in schools.
White House officials have emphasised that no single measure - even an assault weapons ban - would solve a scourge of gun violence across the country. But without such a ban, or other sweeping Congress-approved measures, it's unclear whether executive actions alone can make any noticeable difference.
White House spokesman Jay Carney said: ''It is a simple fact that there are limits to what can be done within existing law.
''Congress has to act on the kinds of measures we've already mentioned because the power to do that is reserved by Congress.''
Mr Obama will announce his proposals on Thursday morning, Melbourne time, at the White House, flanked by children who wrote to him about gun violence following the massacre of 20 students and six adults at Sandy Hook Elementary School.
Law enforcement officials, mayors from across the US and supportive congressional politicians are also expected to attend.
According to a lobbyist, Mr Obama will present a three-part plan focused on gun violence, education and mental health. AP, with BLOOMBERG