Amazon.com Inc. (AMZN) faces an uphill task to beat China internet giant Alibaba Group (BABA) for e-commerce supremacy, according to brokerage Morgan Stanley.

In a research note, reported on by Barron’s, analyst Brian Nowak and his colleagues said that the two internet retail titans will look to power their respective growth prospects by battling it out in mushrooming, up-and-coming markets. India and Latin America were identified as core regions for  “the next $5 trillion battleground.”

Nowark and his team noted that both Amazon and Alibaba have begun “planting seeds” in Latin America and Australia, adding that the U.S. giant is currently ahead in India while its Chinese rival has the lead in Southeast Asia. However, the analysts also warned that Amazon has more riding on this expensive battle for global e-commerce domination.

According to their calculations, the U.S. company is more dependent on boosting international sales because Alibaba still has plenty more headroom to grow in its domestic market. International retail sales are expected to make up 105% of Amazon’s EBIT growth over the next four years, the analysts claimed, while Alibaba can generate 102% of its profit growth over the same timeframe just from its home market. (See also: Buy Alibaba, Not Amazon: Short-Seller Citron.)

Source: Barron's/Morgan Stanley

At present, international sales, excluding the U.K., Germany and Japan, already count for 29% of Amazon’s core revenues, according to Morgan Stanley. If the Seattle, Washington-based company is to continue to grow over the next decade, the brokerage added that it is paramount that it continues to expand its global reach.

Nowark and his colleagues predicted that by 2027 Amazon’s “total addressable market” will expand from $8.9 trillion to $15.9 trillion based on its global growth prospects. In contrast, the analysts forecasted that Alibaba’s revenue opportunities can expand from $10.6 trillion this year to nearly $24 trillion by 2027, simply by making further inroads in China. (See also: Flipkart Board Backs Walmart Offer Over Amazon.)