President Joe Biden on Monday announced a series of measures to crack down on "ghost guns" in his latest effort to curb firearms violence in the US, once again calling on Congress to pass stricter gun laws.
"Law enforcement is sounding the alarm. Our communities are paying the price," Mr Biden said at a White House event attended by survivors of gun violence and families of victims, including those from Sandy Hook.
Mr Biden briefly held up a pieces of a gun from a "build buy shoot" kit, noting how easy it is to construct an unserialised and hard-to-trace weapon.
Police last year reported 20,000 ghost guns to the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) as having been recovered from criminal investigations.
The home-made gun is "the weapons of choice for many criminals", Mr Biden said.
"We're going to do everything we can to deprive them of that choice. And when we find then, put them in jail for a long, long time," he said.
Mr Biden has repeatedly pushed for more strict federal gun laws. In his latest budget proposal, cities would receive more funding for crime prevention and intervention.
The president at the event once again called on lawmakers to pass universal background checks, ban assault-style and high-capacity magazines, and to eliminate gun manufacturers' liability.
But Congress has been deadlocked on gun laws for years, and Mr Biden faces an uphill battle in getting meaningful legislation passed as Capitol Hill remains well divided over the issue.
In 2020, the most recent year statistics are available, guns killed more than 45,000 people in the US. About 54 per cent of these deaths were suicides and 43 per cent were homicides.
The new rule will require licensed dealers to convert ghost guns already in circulation into serialised firearms, regardless if that weapon was made from individual parts, a kit or a 3D printer.
"All of a sudden, it's no longer ghost. It has a return address," Mr Biden said.
The sale of "buy build shoot" kits, which people can buy without a background check and use to assemble a firearm within 30 minutes, will be banned.
The legislation will also update the definitions of "frame" and "receiver" so that dealers selling these kits must become federally licensed and run a background check before any sale.
The rule requires dealers to retain records for as long as they are in business, expanding on the 20-year limit. More than 1,300 firearms in the US are untraceable every year because the dealer destroyed the records that were more than 20 years old, the White House said.
In an opinion piece published by USA Today, Attorney General Merrick Garland said the new laws will save lives and help officials solve cases.
"These changes will make it harder for criminals and other prohibited persons to get their hands on untraceable guns. They will help ensure that law enforcement officers can get the information they need to solve crimes," Mr Garland said.
"These changes are long overdue."
Mr Biden on Monday also nominated former US attorney Steve Dettelbach to head the ATF, which is responsible for enforcing the federal government's gun laws.
Agence France-Presse contributed to this report