The online retail behemoth said sales hit $155.7 billion in the January-to-March period, but its share price dropped as much as four percent in after-hours trading on Wall Street.

Amazon Web Services, the company's hugely successful cloud business, saw sales jump 17 percent to $29.3 billion, but the gain was slightly below expectations.

"We're pleased with the start to 2025, especially our pace of innovation and progress in continuing to improve customer experiences," CEO Andy Jassy said, highlighting new AI offerings including the next-generation Alexa+ virtual assistant.

Amazon said it had launched several AI initiatives during the quarter, including Amazon Nova generative AI models, while expanding its Project Kuiper satellite network to compete with Elon Musk's Starlink.

Looking ahead, Amazon forecast second-quarter net sales between $159 billion and $164 billion, representing solid growth of seven to 11 percent. But this was lower than what analysts had expected.

The outlook is especially sensitive for investors with speculation high on how the wave of high trade tariffs announced by President Donald Trump's administration will affect Amazon's performance.

Trump has most notably slapped 145 percent levies on China, where many US-bound products are made, though he as given exceptions on electronics and other items for now.

There is also uncertainty around whether tariffs will slow spending -- the US economy already showed a contraction in the first quarter of the year.

Jassy said the company had yet to see any reduction in demand since Trump announced his tariffs a month ago even if "to some extent, we've seen some heightened buying in certain categories" as shoppers anticipate price hikes.

Still, "most sellers (on Amazon) just haven't changed pricing yet," he added, while insisting that Amazon wasn't particularly exposed to China.

A report earlier in the week that Amazon was going to display the extra cost of the levies for customers on its platform drew a furious response from the White House.

Amazon executive chairman Jeff Bezos called Trump to defuse the drama, and the company quickly said it had no intention of executing the plan.

Advertising, usually dominated by rivals Google and Meta, was a bright spot in the quarter with sales up 19 percent year-on-year.