US retail giant Walmart has revealed plans to partner with ride-hailing services Uber and Lyft to fulfill deliveries of its online order, in an effort to speed up its shipment times and better compete with rivals like Amazon as the online retailer moves increasingly into the grocery market.

Test deliveries will begin in the next two weeks in stores in the areas around Denver, Colorado and Phoenix, Arizona. Walmarts warehouse brand, Sams Club, has already run a similar pilot scheme using startup Deliv to dispatch groceries to enterprise customers in the Miami, Florida area.

“Were thrilled about the possibility of delivering new convenient options to our customers, and about working with some transformative companies in this test,” said Michael Bender, executive vice president and chief operating officer for Walmart Global eCommerce. “Well start small and let our customers guide us, but testing new things like last-mile delivery allows us to better evaluate the various ways we can best serve our customers how, when and where they need us.”

The pilot will see customers paying a standard $7 to $10 (£5 to £7) delivery charge, and customers will be alerted when their order is being delivered. As Amazon invests more and more capital in the grocery market, introducing services like Dash Buttons and Prime Fresh, which promises same-day delivery, Walmart is fighting back to maintain its spot as the worlds largest retailer.

In April, the company introduced a free curb-side pickup service for groceries in eight new cities, with plans to add another 14 new markets to the service by the end of June. Walmart also recently introduced a subscription-style service, where customers can pay $49 annual fee to get their groceries delivered within two days, although this charge can increase based on use.

While Amazon may see groceries as one of its next key markets to dominate, Walmart is unlikely to take the challenge lying down, and even Amazon could struggle to compete with the massive infrastructure and brand dominance that Walmart commands.