Walmart is expanding into restaurant delivery services, beginning with on-demand access to sub sandwiches from its in-store locations.

The retailer started offering meals from Subway outlets inside Walmart stores roughly a month ago, according to Tracy Poulliot, vice president of e-commerce and marketing. The goal is to extend this service across all 1,400 Subway spots in Walmart stores by the end of July.

Business Insider was the first to report on Walmart's trial of restaurant delivery options.

Shoppers can order Subway items for quick delivery directly through the Walmart app. During the test phase, many users bundled these meals with grocery purchases and other last-minute needs in one transaction, Poulliot noted.

"We are seeing a lot of customers purchase their Subway meals in addition to their groceries," she shared with reporters on Thursday at the company's Bentonville, Arkansas headquarters.

Walmart has invested years in growing its delivery network, now providing fast options for items ranging from produce to household goods across its 4,600 U.S. stores. The service relies on a combination of independent contractors via the Spark app and store staff for order fulfillment and home deliveries.

Subway restaurants have operated within Walmart stores for around two decades, as noted by Damien Harmon, president of Subway North America, in a video presentation.

Harmon shared feedback from a franchisee running multiple in-store Subways, who described the delivery feature as a fresh growth opportunity that helps reach customers more conveniently.

Executives indicated on Thursday that they are open to broadening Walmart's restaurant delivery efforts further.

The company is exploring an integration with its AI tool Sparky to let users request restaurant orders through simple prompts, Poulliot explained.

Other chains like Dunkin' Donuts, McDonald's, and regional spots such as Wienerschnitzel also have locations in select Walmart stores.

Walmart sees opportunities to extend the service to eateries outside its own properties, according to Greg Cathey, senior vice president of digital fulfillment transformation.

"You can draw a circle around most Walmart stores, and almost all quick-service restaurant brands are located within five miles," he said.