Walmart is launching a global money transfer service called Walmart2World in a partnership with MoneyGram International. The move expands on its domestic money service, launched roughly four years ago to serve America's unbanked population.

Walmart2Walmart, the U.S.-based platform, allows customers to transfer funds between Walmart locations domestically, sending as much as $2,500 at a time. The new Walmart2World will allow customers to relay funds to people in more than 200 countries.

"We probably really underestimated the impact we could really make in this business, which hasn't seen a ton of innovation for a long time," Kirsty Ward, the vice president of Walmart Services, told CNBC.

With Walmart2World, the retailer aims to serve the roughly 2 billion individuals across the globe who the World Bank's Global Findex database classifies as unbanked. Common uses for wiring money include paying bills and remitting money to families or friends overseas.

The new service aims to beat out its competitors with speed and low, stable prices.

Walmart2World will charge an individual $4 to send up to $50, $8 to send amounts between $51 and $1,000, and $16 to send $1,001 to $2,500. And unlike some other international transfer services, Walmart's fees will remain the same regardless of where the sender and receiver are located.

Ward says that "clear and transparent menu-board pricing" is key to the initiative.

Walmart2World also promises delivery of funds in 10 minutes or less, unlike some services that can take as long as three days. MoneyGram's network of agents across the globe will help serve the populations where Walmart doesn't always have a presence.

The initiative could ultimately drive more foot traffic to Walmart stores, boosting sales. "We would love for customers to choose who they shop with based on how we can save them money. ... If they choose to spend [their savings] in Walmart, that's fantastic," Ward said.

Less than 1 percent of Walmart's annual net sales came from fuel and financial services, which includes wire and money transfers.

Companies like Western Union and MoneyGram, meanwhile, have built their businesses entirely around the idea.

E-commerce giant Amazon is reportedly looking to take a different approach to reach potential shoppers who don't have bank accounts. The Wall Street Journal reported last month that Amazon was in early talks with financial institutions including J.P. Morgan Chase to help launch "checking-account-like products" aimed at younger and unbanked customers.

Walmart2World is scheduled to roll out to all of Walmart's 4,700 U.S. stores, on Walmart.com, and to the Walmart mobile app later this month.