Amazon is expanding its same-day grocery delivery service to 1,000 cities and towns across the U.S., the company said Wednesday. It's also introducing thousands of perishable grocery items to its offerings,

The online retail giant plans to expand the service to 2,300 U.S. locations by year’s end in its quest to compete with Walmart.

Amazon called the move 'one of the most significant grocery expansions' for the online retailer as it introduces thousands of perishable items into its existing network.