US President Joe Biden announced Monday new measures cracking down on so-called "ghost guns" with an executive order to increase restrictions on the difficult-to-trace weapons that can be assembled at home.

At a White House gathering that brought together families of shooting victims, Biden said the number of "ghost guns" reported by the police had increased tenfold between 2016 and 2021.

While stressing he was not opposed to the right to bear arms as allowed for in the Second Amendment to the constitution, Biden criticized the powerful National Rifle Association (NRA) gun lobby for having described his proposal as "extreme".

The rule will make it harder to obtain untraceable guns

The new rule demands that weapons part kits that can be assembled into a working firearm will be subject to the same requirements as commercially available, fully assembled guns, administration officials said.

For example, dealers selling "ghost gun" kits will now have to conduct a background check on prospective buyers.

Gun kit manufacturers must also include a serial number on key weapon components, while licensed dealers who take a "ghost gun" into their inventory must add a serial number, the US Justice Department explained in a statement.

The new rule states that federally licensed dealers of firearms must keep records for as long as they are in business, rather than for a 20-year period, as is currently the case.

"This rule will make it harder for criminals and other prohibited persons to obtain untraceable guns, will help ensure that law enforcement officers can retrieve the information they need to solve crimes, and will help reduce the number of untraceable firearms flooding our communities," pointed out Attorney General Merrick Garland.

11,700 people died by firearms since the beginning of 2022

From January 2016 to December 2021, the US Bureau of Alcohol, Tobacco and Firearms (ATF) received approximately 45,240 reports of suspected privately made firearms recovered by law enforcement, the Justice Department noted. Those reports were linked to at least 692 homicide or attempted homicide investigations.

Over the past five-year period, the ATF could only trace 0.98% of suspected "ghost guns" handed in by law enforcement to an individual purchaser, the department added.

According to the organization Gun Violence Archive, more than 11,700 people have died by firearms since the beginning of the year in the United States, including suicides. 

Over the whole of 2021, the number rose to 45,000 dead, said the archive, a figure which has prompted the White House to speak of an "epidemic".