Under pressure to stop selling guns after recent shootings at two Walmart stores in Mississippi and Texas, the retailer's CEO, Doug McMillon, on Thursday said the U.S. should revisit banning assault weapons. 

In prepared remarks that came with Walmart's quarterly earnings, McMillon gingerly stepped into the political storm surrounding guns and an epidemic of mass shootings in the U.S. 

"In the national conversation around gun safety, we're encouraged that broad support is emerging to strengthen background checks and to remove weapons from those who have been determined to pose an imminent danger," he stated. "The reauthorization of the assault weapons ban should be debated to determine its effectiveness in keeping weapons made for war out of the hands of mass murderers."

Commonly called the assault weapons ban, the Public Safety and Recreational Firearms Use Protection Act was adopted in 1994 and expired a decade later. The now-lapsed law prohibited the manufacture or sale for civilian use of certain semi-automatic weapons that could be converted to fire automatically and magazines that could accommodate 10 rounds or more.

Walmart, which has for years declined to break out its gun sales from its overall sales figures, on Thursday estimated it represents about 2% of the market for firearms. That puts Walmart outside at least the top three sellers in the industry, estimated the company. Walmart's share of the U.S. ammunition market comes to about 20%, McMillon said. The Arkansas-based company's total global net sales were about $500 billion last year.

© 2019 CBS Interactive Inc. All Rights Reserved.