Amazon is expanding its same-day grocery delivery service to 1,000 cities and towns across the U.S., the company said Wednesday.

The move places Amazon in more direct competition with Walmart+ and Instacart by lowering friction for customers to buy fresh food alongside nonfood items in a single checkout. Lower order minimums and free same-day delivery for Prime members could also nudge consumers toward Amazon and pressure rival delivery margins.

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.