For Instacart, the leading U.S. grocery delivery company, being fast may not be fast enough.

The $39 billion-valuation startup is planning to launch a pilot program to provide delivery of groceries or convenience items in 15 minutes or less to U.S. customers, said two people with direct knowledge of the plan. As a part of the proposed program, Instacart would pay a company that manages couriers to quickly deliver goods from the same grocery stores whose merchandise Instacart already offers to its existing customers, most of whom currently receive their orders within two hours or less.

Instacart recently asked several logistics companies to submit proposals for the ultrafast delivery program, with plans to launch an early version of the service in a U.S. city as early as February, the people said. If it did so, Instacart would thrust itself into competition with ultrafast grocery delivery startups including Jokr, Getir and Gorillas. If Instacart stuck with the program, it would suggest that the instant delivery model, which has faced some skepticism, could be here to stay, even as the startups in the sector burn through venture capital.