Walmart is expanding its drone delivery service across six states, the retail giant said Tuesday. Walmart said the service has the potential to reach 4 million US households and deliver over 1 million packages by drone in a year.

Up to now, the drone service has only been available in parts of Arkansas. Walmart now is expanding its drone delivery network to 34 sites across six states by the end of the year. In addition to Arkansas, customers in those locations in Arizona, Florida, Texas, Utah and Virginia will be able to order packages delivered by drone to their homes.

Drone delivery will be available between the hours of 8 a.m. and 8 p.m. for a fee of $4. Walmart said customers will be able to choose from tens of thousands of items like groceries, diapers and over-the-counter medicine. Customers can order items totaling up to 10 pounds and have it delivered by drone in as little as 30 minutes. 

"If it fits safely it flies," the company said.

Other companies like UPS, Amazon and Alphabet are also working on expanding their own drone delivery initiatives. 

Google's parent company Alphabet began flying packages with Wing, its drone delivery service, to Dallas-area residents in April after having previously delivered over 200,000 packages via drone in Australia, Finland and Virginia. UPS drones were flying medicine to CVS customers' homes in 2019. The same year, Amazon unveiled a newly redesigned Prime Air drone -- part of Amazon's drone delivery project that has since been hampered by a series of crashes and issues with its Prime Air unit in the UK. 

In 2020, the FAA announced a set of rules in the US addressing drone safety concerns -- which could help bring drone delivery services into the mainstream.