Walmart has announced that it will halt sales of ammunition for handguns and some military-style rifles used in some hunting rifles, calling the status quo on guns in the United States "unacceptable".

The moves came a month after a deadly shooting at a Texas Walmart claimed 22 lives, a tragedy that has been followed by subsequent attacks, including another shooting over the weekend in west Texas that left seven dead.

Chief Executive Doug McMillon called on Congress and the White House to enact "common sense" measures, including stronger background checks for gun purchases.

"As we've seen before, these horrific events occur and then the spotlight fades. We should not allow that to happen," Mr McMillon said in a statement. "Congress and the administration should act."

Walmart expects the changes on ammunition to lower its market share of bullets from around 20% to a range of 6-9%.

The company plans to continue to sell long-barrel deer rifles and shotguns and much of the ammunition used in these guns, leaving its stores "even more focused on the needs of hunting and sport shooting enthusiasts," Mr McMillon said.

The moves announced followed earlier actions by Walmart to restrict access to some weapons, including a decision in 1993 to halt handgun sales in all states but Alaska and in 2015 to end sales of semiautomatic guns of the sort used in mass shootings.

Today, Walmart said it was also ending sales of handguns in Alaska. However, Walmart has resisted calls to completely halt gun sales.

As a gun owner, Mr McMillon added: "We understand that heritage, our deeply rooted place in America and our influence as the world's largest retailer. And we understand the responsibility that comes with it."