Updated at 5:45 p.m. with additional information

WASHINGTON — The Justice Department issued a proposal on Friday to ban bump stocks, the rifle accessory used in the Las Vegas shooting that allows a semi-automatic gun to fire at nearly automatic rates.

The announcement comes one day before demonstrations in Washington and other cities aimed at pressuring Congress to curb access to guns used in a spate of recent mass shootings.

President Donald Trump directed the department to draft regulations banning the device in February, more than four months after the Las Vegas shooter killed nearly 60 people at an outdoor concert in October. Bump stocks were not used in the Florida shooting in February or the massacre at the Sutherland Springs church in November.

Trump tweeted his support after Attorney General Jeff Sessions announced the ban.

Obama Administration legalized bump stocks. BAD IDEA. As I promised, today the Department of Justice will issue the rule banning BUMP STOCKS with a mandated comment period. We will BAN all devices that turn legal weapons into illegal machine guns. — Donald J. Trump (@realDonaldTrump) March 23, 2018

"Obama Administration legalized bump stocks. BAD IDEA," he tweeted. "As I promised, today the Department of Justice will issue the rule banning BUMP STOCKS with a mandated comment period. We will BAN all devices that turn legal weapons into illegal machine guns."

The Justice Department's proposal would reverse a 2010 decision by the Bureau of Alcohol, Tobacco, Firearms and Explosives that determined bump stocks do not fall within the definition of a machine gun.

Gun stores reported a spike in sales of the devices after the Las Vegas massacre, as gun owners became aware of the product and some grew concerned about an impending ban. Texas-based Slide Fire, a leading manufacturer, offered Cyber Monday and Valentine's Day deals.

"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," Sessions said in a statement.

The ban would take effect after a required 90-day comment period. Once finalized, bump stock owners would be required to surrender or destroy their device.

Democrats have seen the Justice Department's review as an effort to deflate congressional efforts aimed at a permanent ban.

Sen. Dianne Feinstein, the top Democrat on the Senate Judiciary Committee, authored a bill to ban bump stocks. The legislation, which has bipartisan support, has not moved forward.

"The only way to guarantee bump stocks are banned is to pass a law," she said in a statement earlier this month. "If Republicans truly wanted to get these dangerous devices off the streets, they would support our legislation."

Gun owners in Texas question how to enforce a ban on the accessories. Stores around the country reported an uptick in sales after the Vegas shooting.

In Austin, Central Texas Gun Works owner Michael Cargill's entire inventory — 23 bump stocks — sold out within 24 hours as the debate ramped up in Congress.

"As a private citizen, I am going to resist," he said in October. "We are going to resist, and we are not going to comply."

Congress passed its own gun-related measures tied in the spending deal that Trump signed into law on Friday.

The measure included Texas Sen. John Cornyn's gun background check bill, filed in response to the Texas church massacre in November. The bill also clarifies language to allow the Centers for Disease Control and Prevention to research gun violence and provides additional funding to beef up security in schools.