The portal will have one- and two-hour delivery windows and include grocery delivery from services like Amazon Fresh and Whole Foods Market, the company said.
"I think that this of going to be a game changer, and it will grow into one of the most loved benefits of Prime," said Stephenie Landry, vice president of grocery delivery.
Amazon said in 2017 it was ending its Fresh grocery delivery service for select areas. Landry, however, said the business is very much growing and has expanded this year to areas like Nashville, Orlando and Las Vegas.
Users would still have an option to shop groceries via other portals such as Prime Now, Amazon said.
Amazon has been cutting delivery times to one day for its Prime loyalty members, a way to outmanoeuvre rivals such as Walmart Inc
Costs for Amazon's one-day delivery will nearly double to $1.5 billion (£1.2 billion) during the holiday quarter from the second quarter, Chief Financial Officer Brian Olsavsky said last week.