DoorDash (NASDAQ: DASH) and Costco Wholesale Corporation (NASDAQ: COST) have expanded their partnership to include all Costco warehouse locations across the United States, enabling same-day delivery through the DoorDash app.

Costco members can now order more than 4,000 products — including groceries, household essentials, electronics, seasonal merchandise and Kirkland Signature items — from their local Costco warehouse via DoorDash. To place an order, members open the DoorDash app, select their local Costco warehouse and link an active Costco membership.

The U.S. launch extends an existing international partnership between the two companies that already covers Australia, New Zealand, Sweden, Iceland and Puerto Rico.

"By pairing Costco's quality, value and selection with DoorDash's reach and local delivery network, we're giving members more flexibility in how they shop," said Mike Goldblatt, Vice President of Enterprise Partnerships at DoorDash.

With the addition of Costco, DoorDash says it now partners with 8 of the 10 largest food retailers in North America, according to Progressive Grocer's PG 100 ranking.

Consumers without a Costco membership can purchase one through Costco.com before linking their account on DoorDash to complete a purchase.