The Justice Department on Tuesday issued its final rule banning bump stocks — a device that was prominently used in the Las Vegas shooting massacre last year, which allows a semi-automatic rifle to work like a machine gun.

Acting Attorney General Matt Whitaker announced the rule in a statement Tuesday.

"We are faithfully following President Trump’s leadership by making clear that bump stocks, which turn semiautomatics into machine guns, are illegal, and we will continue to take illegal guns off of our streets," Whitaker said.

Later, at a school safety event at the White House, he called it a "big victory" for Trump's administration.

Trump had urged the federal government to ban bump stocks this past spring following a deadly Valentine's Day shooting at a high school in Parkland, Florida, that left 17 dead. However, the device gained notoriety when a lone gunman killed 59 people and injured at least 527 others attending a country music festival in Las Vegas in October 2017. The shooter, Stephen Paddock, had 22 semi-automatic rifles and 14 of them were equipped with bump stocks. They allowed him to fire the rifles continuously with a single pull of the trigger, resulting in the deadliest mass shooting in modern U.S. history.

"We've taken important steps, but much work remains to be done, as always," Trump said of his administration's actions on guns and school safety at the White House event.

The rule amends the regulations of the Bureau of Alcohol, Tobacco, Firearms, and Explosives to include all bump-stock-type devices and re-classify them as machine guns. The move would ban individuals from owning or selling bump stocks, or similarly designed devices. Once the rule becomes effective, anyone owning one would be required to destroy it or turn it over to a local ATF office, the DOJ said.

The rule will become final 90 days after it is published in the Federal Register.

Whitaker also said on Tuesday at the White House that bump stock owners would have 90 days to destroy their devices or to turn them. The Justice Department said the ATF plans to post instructions on how to properly destroy the device on its website.

Matt Deitsch, the co-founder of March for Our Lives, a youth-led movement against gun violence created after the Parkland shooting, said the ban “took far too long,” but that it was a step in the right direction.

"This is a good first step, but it only scratches the surface of the reforms we need to end the epidemic of gun violence in America once and for all. We welcome this new policy, but we cannot allow the current Administration, members of Congress, or the NRA to use this as cover while they stall on reforms that our country and communities need immediately,” Deitsch said.

The National Rifle Association, however, said in a statement to NBC News that the rule should have offered "amnesty" to current bump stock owners because of a 2010 decision by the ATF that found bump stocks did not amount to machine guns and could not be regulated unless Congress amended existing firearms law or passed a new one.

“We are disappointed that this final rule fails to address the thousands of law-abiding Americans who relied on prior ATF determinations when lawfully acquiring these devices,” Jennifer Baker, an NRA spokeswoman, said. "As we recommended to ATF in our comments on the proposed rule, Congress made it possible for the Attorney General to provide amnesty for firearms regulated under the National Firearms Act. The Attorney General should have exercised that authority to provide a period of amnesty under this rule."