President Donald Trump's decision comes as pressure mounts on the US administration to take action after last week's shooting at a Florida High School killed 17 people.
President Donald Trump said on Tuesday his administration would take steps to ban an accessory that enables a rifle to shoot hundreds of rounds a minute as he considers additional firearms restrictions after last week's school shooting in Florida.
Tightening gun laws would mark a change in course for Trump, who has championed gun rights during his campaign and presidency.
The mass shooting at a Parkland, Florida, high school – where 17 people were killed – has reignited a drive to curb access to firearms.
Trump directed the US Justice Department to quickly complete a proposed rule that would treat "bump stocks" as machine guns, which could effectively outlaw them in the US.
TRT World's Harry Horton reports.
"I expect that these critical regulations will be finalised very soon," Trump said at a White House event.
"We cannot merely take actions that make us feel like we are making a difference, we must actually make a difference."
The move came in response to an October massacre in Las Vegas, where a gunman used a bump-stock-equipped rifle to kill 58 people.
It put Trump at odds with the powerful National Rifle Association, which has opposed bump-stock restrictions, and would allow him to bypass Congress, where a bump-stock ban has failed to advance.
The president deserves thanks for taking an important first step on gun safety laws by directing the AG to ban bump stocks. Let’s hope expanded background checks are next so we can keep military-style guns out of the hands of terrorists, domestic abusers and the mentally ill.— Joe Scarborough (@JoeNBC) February 20, 2018
His announcement came shortly after White House spokeswoman Sarah Sanders said Trump would not rule out other options as well, such as raising the minimum age for rifle buyers or banning the AR-15-style "assault rifles" used in a number of high-profile mass shootings, including last week's shooting in Florida.
The suspect in that shooting, 19-year-old Nikolas Cruz, was armed with an AR-15 style rifle that he had purchased legally, authorities said.
Under federal law, people must be at least 21 years old to purchase a handgun from a licensed dealer. But they only have to be 18 to buy a rifle or shotgun.
Trump still hasn't done anything to prevent another mass shooting from happening. Banning bump stocks won't stop another shooting. Banning assault weapons might. Why doesn't Trump wanna protect Americans? Or even try to? Oh, because he's a traitor. #TrumpColluded #GunReformNow— Scott Dworkin (@funder) February 20, 2018
The NRA said it could not comment on Trump's proposed bump-stock ban until it saw the specifics of the regulation.
Student and parent activists from the high school in Parkland, Florida, near Fort Lauderdale were expected to stage a rally on Wednesday at the statehouse on Wednesday, about 725 km to the north of the school.
Fourteen students and three educators were killed and 15 other people were wounded in the February 14 attack.
Nikolas Cruz, 19, a former student expelled from Stoneman Douglas High for disciplinary problems, was arrested and charged with 17 counts of premeditated murder.
On Tuesday dozens of students and parents from the Florida high school arrived in the state capital of Tallahassee to lobby for a ban on assault-style rifles.
Last week's massacre, the second-deadliest shooting at a public school in US history, has inflamed a national debate about gun rights and prompted young people from Marjory Stoneman Douglas High School and across the United States to demand action for stricter firearms controls.
Students from the South Florida high school were tearful as they stepped down from the bus in Tallahassee to be welcomed with waves, cheers and somber applause from fellow teens.
"We're here to make sure this never happens again," Diego Pfeiffer a senior at Stoneman told the crowd that included hundreds of students from a Tallahassee high school over a crackling microphone.
On Tuesday, less than a week after the shooting, the Republican-controlled Florida House of Representatives rebuffed a bid to bring up a bill to block sales of assault-style rifles in the state.
"I am not going back to school until lawmakers, and the president, change this law," said Tyra Hemans, a 19-year-old senior, who traveled to the state capital.