The devices, which harness the recoil of a semi-automatic rifle's discharge to make the trigger fire faster, effectively turn the weapons into machine guns, which are illegal, the Justice Department said.

Bump stocks allow a "shooter of a semi-automatic firearm to initiate a continuous firing cycle with a single pull of the trigger," the department said in a statement.

The devices were used by Las Vegas shooter Stephen Paddock on a dozen rifles he deployed to kill 58 people and wound 500 at an open concert last year, the deadliest mass shooting in recent US history.

Bump stocks allowed him to fire at a rate of nine bullets a second, before he turned his weapons on himself.

Following another gun massacre at a school in Parkland, Florida, in February this year that left 17 people dead, more than a million people demonstrated for stricter gun control.

President Donald Trump announced his intention to ban bump stocks but refused restrictions on semi-automatic assault weapons.

The National Rifle Association, the powerful gun lobby, did not mount any major campaign to counter a bump stock ban.

Anyone owning a bump stock will have 90 days after the new regulation is published in the Federal Register to either hand in their devices to the authorities, or destroy them.

While a third of US households possess a firearm, the majority of Americans favor tougher gun controls such as background checks for people seeking to buy a weapon.