US President Donald Trump has signed an order to ban bump-stock devices, which were used by a gunman who killed 58 Las Vegas concert-goers last year.
Such devices enable a rifle to shoot hundreds of rounds a minute.
Speaking at the White House, Mr Trump said he had directed the justice department to propose a law to make the accessories illegal.
The gun control debate took on a new urgency after 17 people were killed at a school in Florida last week.
Students and parents affected by the massacre at Marjory Stoneman Douglas High School are planning a demonstration in the state capital of Tallahassee on Wednesday.
‘We’re not gonna back down’
By Paul Blake, BBC News, South Florida
In all around 100 students, spread across three buses, made the journey of more than seven hours to the state capital.
For many of these students, it is their first time to the capitol building in Tallahassee – much less to lobby their lawmakers over a national issue.
There is an excitement among the students, who sense that they may be on the cusp of starting a national movement.
“We’re travelling to our state capital to make sure that none of these people that we grew up with – that we’ve known our whole lives – die in vain,” Julia Salomone, 18, said confidently.
So how do the students expect the politicians to receive them? “Honestly, I feel like they’re gonna be overwhelmed by us because they’re going to see in our faces our determination, our commitment to this, because this is all we’re fighting for right now,” 16-year-old Rain Valladares said. “They’re gonna look us in the face and see that we’re not gonna back down.”
What did Trump say?
At an event on Tuesday recognising the bravery of law enforcement, Mr Trump said he had directed Attorney General Jeff Sessions to finalise new guidelines to declare bump stocks illegal “very soon”.
“The key in all of these efforts, as I said in my remarks the day after the shooting, is that we cannot merely take actions that make us feel like we are making a difference, we must actually make a difference,” he said.
“We must move past clichés and tired debates, and focus on evidence-based solutions and security measures that…