The move, which was initially reported by Reuters on Sunday, points to how the U.S. firm's China strategy is evolving after it decided earlier this year to stop operating a marketplace in the country for domestic-selling merchants.

In April, it said it would instead increase its focus on selling goods from abroad to Chinese buyers and on its other businesses in the country like cloud services.

Amazon had found it difficult to compete with entrenched, home-grown players such as Alibaba Group Holding Ltd's Tmall and its rival marketplace from JD.com Inc. In a sign of Tmall's dominance, Amazon opened an online store on the platform in 2015.

Its decision to open a store on Pinduoduo, however, points to how the four-year-old startup has disrupted Alibaba and JD.com's dominance of China's e-commerce market through its popularity with China's rural residents.

Competition between the three firms have heated up in recent months and Pinduoduo, which woos customers with deep discounts and group-buying deals, suffered an $11 billion slump in value last week after it posted a much wider-than-expected quarterly loss that stemmed from efforts to fight rivals with heavy subsidies.

"The Amazon Global Store pop-up store on Pinduoduo provides customers with a curated selection of about 1,000 overseas products with competitive prices, authenticity guarantee and convenient shipping," an Amazon spokeswoman said in a statement.

"We look forward to enabling customers to enjoy cross-border shopping through this store, in addition to more deals and tens of millions of products available on z.cn," she said, referring to the website Amazon.cn.

A spokeswoman for Pinduoduo said that the initiative was part of an aim to "offer equal opportunIties for our users to access global products".

"We are committed to working with our partners as part of our global outreach to offer best value-for-money products worldwide to our users," she said.

By Brenda Goh