Several bump stocks were used by the gunman who shot concert-goers in Las Vegas on 1 October, killing 58 people and injuring more than 850. ATF also issued classification decisions concluding that other bump-stock-type devices were not machineguns, including a device submitted by the manufacturer of the bump-stock-type devices used in the Las Vegas shooting.
The Trump administration got something right, but not without a dig at the former president Barack Obama's administration.
In his tweet, Trump castigated the Obama administration for that previous ATF ruling, in effect criticizing his predecessor for not limiting firearms after years in which Trump assailed Obama as opposing gun rights.
The move comes a day before hundreds of thousands of people are expected to descend on the capital to call for stricter gun control in the wake of last month's mass shooting at a Parkland, Fla., high school.
Under the proposal, current owners of bump stocks "would be required to surrender them, destroy them, or otherwise render them permanently inoperable".
Specifically, the DOJ is looking to change the Bureau of Alcohol, Tobacco, Firearms and Explosives regulations to clarify that bump stocks do actually fall under the definition of "machinegun".
China prepares to hit back at Trump's tariffs; stocks keep falling
These hurdles would only get higher if a trade war were to erupt between the United States and China . The Trump administration, true to form, wants to cut the program instead.
At the beginning of the tweet, President Trump noted that the Obama Administration allowed for the legal sale of bump stocks.
"After the senseless attack in Las Vegas, this proposed rule is a critical step in our effort to reduce the threat of gun violence that is in keeping with the Constitution and the laws passed by Congress", Mr Sessions said.
Sessions' action opens a 90-day public comment period before the regulation can become final.
The National Rifle Association has supported bump stock regulation, but has not endorsed Mr. Trump's proposed ban, saying it was waiting review any rule changes.
Trump signed an order on February 20, less than a week after the mass shooting at Marjory Stoneman Douglas High School in Parkland, Florida, directing the Justice Department to make the change.
For months, President Trump has urged the Justice Department to pursue the bump stock ban. Now under the law, automatic weapons made after 1986 are illegal under the Firearm Owners' Protection Act, meaning new automatic weapons for civilian use can not be manufactured.