President Trump Donald John TrumpBubba Wallace to be driver of Michael Jordan, Denny Hamlin NASCAR team Graham: GOP will confirm Trump's Supreme Court nominee before the election Southwest Airlines, unions call for six-month extension of government aid MORE on Friday announced that the Department of Justice (DOJ) would issue a new rule banning bump stocks.

In a tweet, Trump announced that he was directing DOJ to reverse a 2010 decision by the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) that classified bump stocks as firearm parts so the devices could be banned under current laws that prohibit owning fully automatic weapons.

Trump blamed the legalization of bump stocks on the Obama administration.

ADVERTISEMENT

"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," Trump tweeted.

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

The decision Friday follows a letter sent by GOP senators in October urging the administration to review the decision after a mass shooter used the device in killing 58 people at a country music concert in Las Vegas.

Bump stocks are used to modify semi-automatic weapons so they fire more rapidly.

"Unfortunately, we are all now keenly aware of how this device operates and believe that this renewed review and determination will keep our citizens safe and ensure that federal law is enforced," the nine Republicans wrote last year.

Fully automatic weapons have been banned in the U.S. since 1986, but bump stocks were described by the ATF in 2010 as "a firearm part and is not regulated as a firearm under the Gun Control Act or the National Firearms Act.”