Updated at 2:40 p.m.: Revised to include comment from a Bureau of Alcohol, Tobacco, Firearms and Explosives spokesman.

WASHINGTON — On the anniversary Monday of the mass shooting in Las Vegas that left 58 people dead, President Donald Trump said a ban on bump stocks would be enacted in "two or three weeks."

"We're knocking out bump stocks. I've told the NRA ... bump stocks are gone," Trump said Monday at a news conference.

The plastic add-on devices turn semiautomatic weapons into machine guns. Las Vegas shooter Stephen Paddock used them last year to fire more than 1,100 rounds of ammunition in 10 minutes.

Most of the bump stocks he used were produced by Slide Fire, a small company outside Abilene that closed its online store in June and has referred customers seeking bump stocks to a Fort Worth-based company called RW Arms.

A spokesman for the federal Bureau of Alcohol, Tobacco, Firearms and Explosives said the Justice Department submitted a proposed final ban on bump stocks to the Office of Management and Budget on Thursday.

That started the clock on a review period that could last up to 90 days but has no required minimum length.

Legislation to ban the devices stalled in Congress. Trump asked Attorney General Jeff Sessions to explore a regulatory ban on bump stocks in February. The measure received 193,297 comments during a public comment period that ended June 27.

National Rifle Association leaders said they were open to limits on bump stocks four days after the Las Vegas shooting.

"Devices designed to allow semiautomatic rifles to function like fully-automatic rifles should be subject to additional regulations," NRA CEO Wayne LaPierre and executive director Chris Cox said in a joint statement.

Sen. John Cornyn sent the ATF a letter in support of the ban, but Sen. Ted Cruz has not taken a public stance.