A memorial near the El Paso, Texas Walmart where 22 people were killed in August during a mass shooting. (AFP)

Walmart will halt sales of ammunition for handguns and some military-style rifles, the company announced Tuesday, calling the status quo on firearms in the United States “unacceptable.”

The moves came a month after a deadly shooting at an El Paso, Texas store claimed 22 lives, a calamity that has been followed by subsequent attacks, including another shooting over the weekend in West Texas that left seven dead.

Walmart also said it will direct consumers not to carry or wear firearms into its stores, a practice that is legal in many states but which has sparked safety scares in recent weeks.

Chief executive Doug McMillon called on Congress and the White House to enact “common sense” measures, including stronger background checks for gun purchases, while signaling the retail giant still plans to sell sporting rifles.

“As we’ve seen before, these horrific events occur and then the spotlight fades. We should not allow that to happen,” McMillon said in a statement.

“Congress and the administration should act.”

The moves stop well short of the outright ban on gun sales that some gun control advocates called for but are significant given Walmart’s size and prominence in many communities in the United States.

The world’s biggest retailer, Arkansas-based Walmart has more than 4,700 stores across America, many in conservative regions where political opposition to gun control is strong.

The hashtag #boycottwalmart was trending Tuesday afternoon on Twitter, while gun control advocates such as Everytown for Gun Safety lauded the move.

The National Rifle Association denounced Walmart’s decision, saying the company had buckled under “the pressure of the anti-gun elites.”

“Lines at Walmart will soon be replaced by lines at other retailers who are more supportive of America’s fundamental freedoms.”

But Democratic presidential candidate Beto O’Rourke, who previously represented El Paso in Congress, called Walmart’s move a “step in the right direction,” adding, “we can’t rely on corporations to stop gun violence. We need universal background checks, we need red flag laws, and we need to buy back every single assault weapon.”

Walmart expects the changes to lower its market share for ammunition from around 20 percent to a range of six to nine percent.

The company will also no longer sell ammunition for short-barrel rifles, which are often used in hunting but can also be used in military-style weapons.

The company will still sell long-barrel deer rifles and shotguns and much of the ammunition they use, leaving its stores “even more focused on the needs of hunting and sport shooting enthusiasts,” McMillon said.

Walmart also unveiled new policies restricting firearms in stores, citing a number of incidents in which shoppers have fled stores after members of the public brandished such weapons in “open carry” states.