President Donald Trump announced Tuesday that he signed a memo directing Attorney General Jeff Sessions to take steps to ban bump stocks, the controversial accessories that essentially transform semi-automatic assault rifles into rapid-fire machine guns.

“After the deadly shooting in Las Vegas, I told the Attorney General to clarify whether certain bump stock devices like the one used in Las Vegas are illegal under current law,” Trump said from the White House podium, noting that process started last fall. “A few moments ago, I signed a memorandum directing the Attorney General to propose regulations to ban all devices that turn legal weapons into machine guns. I expect that these critical regulations will be finalized very soon.”

Trump’s announcement comes almost a week after a teen gunman walked into Marjory Stoneman Douglas High School in Parkland, Florida, and opened fire with an assault rifle, leaving at least 17 dead and 14 injured. That massacre has reignited the gun control debate, via activism spearheaded by the student survivors.

The once-obscure “bump stock” accessory was thrust into the national spotlight after authorities in Las Vegas revealed that the shooter had 12 of them in his arsenal when he gunned down festival-goers on the Strip from his hotel room on Oct. 1, leaving 58 dead and 851 injured.

In the wake of the Vegas attack, lawmakers on both sides of the aisle appeared open to the prospect of outlawing bump stocks altogether. However, as weeks passed and memory of that horrific event began to fade, bipartisan bills in both the House and the Senate stalled.

The onus then fell on state and local governments to regulate bump stocks. Massachusetts became the first state to ban the accessory and similar devices last November. The state of New Jersey and a host of large cities, including Columbia, South Carolina, and Denver have also since passed measures prohibiting the sale and possession of bump stocks.

Trump also used his memo to take a swipe at his predecessor, declaring, “Although the Obama Administration repeatedly concluded that particular bump stock type devices were lawful to purchase and possess, I sought further clarification of the law restricting fully automatic machine guns.”

The memo's language echoes a statement issued by the National Rifle Association after the Las Vegas attack. "Despite the fact that the Obama administration approved the sale of bump fire stocks on at least two occasions, the National Rifle Association is calling on the Bureau of Alcohol, Tobacco, Firearms and Explosives to immediately review whether these devices comply with federal law," the NRA wrote.

Politifact determined that the NRA’s statement on the Obama administration approving the sale of bump stocks was “mostly true.”