New York on Tuesday passed what supporters called the toughest gun ownership law in the country and became the first US state to impose new restrictions in the wake of last month's elementary school massacre in Connecticut.

Lawmakers in the lower house of the State Assembly voted 104-43 in favor of the measure, which had been approved by the upper house in a 43-18 vote late Monday.

Democratic Governor Andrew Cuomo, who rushed through the legislation, welcomed the assembly's "bold statement, coming together in a bipartisan, collaborative manner to meet the challenges that face our state and our nation, as we have seen far too many senseless acts of gun violence."

He told lawmakers ahead of the votes: "The people of this state now are crying out for help on the issue of gun violence."

The measures, which include a full ban on sales of military-style rifles, were linked directly to the national horror at the December 14 massacre of 20 six- and seven-year-olds and six staff at Sandy Hook Elementary School in Newtown, Connecticut.

Those killings sparked a major national debate over the need for curbing America's liberal gun laws. President Barack Obama said Tuesday he would unveil his own proposals on Wednesday.

New York's rapid action on the opening days of its new session grabbed national attention and ramped up momentum for supporters of sweeping new restrictions, particularly regarding assault rifles -- the kind of weapon the Newtown killer used.

The NY Secure Ammunition and Firearms Enforcement Act, or NY SAFE, closes several loopholes in an existing state ban on assault weapon sales.

It reduces the maximum magazine size from 10 rounds to seven and extends the requirement for background checks to all sales, including private deals.

Another notable aspect of the new rules is emphasis on preventing the mentally ill from gaining access to weapons. An existing law allowing judges to order mentally ill people to get treatment was strengthened.

"I think the message out there is so clear after Newtown," State Assembly Speaker Sheldon Silver said as the debate got underway on Monday. "It is an emergency," he said.

However, opponents questioned whether focusing on assault rifles was wise, given that handguns are used far more frequently in crimes. They also accused Cuomo and his allies of violating the US constitution's guarantee of the right to bear arms.

The law "tramples on the constitutional rights of our citizens," Republican assembly member Marc Butler said during the debate on Tuesday.

Advocates of gun control say that rifles designed for firing at a high rate and at multiple targets make it easier for such massacres to take place.

In the run-up to Monday's vote, Cuomo also ridiculed the argument that assault rifles -- which resemble those carried by the military, except that they cannot be fired on full automatic -- are needed by ordinary people, such as hunters.

"No one hunts with an assault rifle," Cuomo said. "No one needs 10 bullets to kill a deer. End the madness."