Apple Watch shipments are expected to drop in the first quarter of 2018 by 20%, according to an estimate from market research firm Geneva Watch.
The company said the number of Apple Watch units in Japan was down 6% from the same period last year.
In contrast, shipments of the Apple Watch were up 20% in the United States.
Geneva said the company expects shipments of Apple Watches in Japan to fall by around 5% in 2018 compared to the same quarter last year, when shipments were up 40%.
Geneva said Apple Watched sales in China grew by 20% year-on-year to around 1.2 million units last quarter.
The report comes just weeks after Apple unveiled its first smartwatch, the $1,399 Apple Watch Series 2.
In its first two weeks of availability, the Apple Watchet was sold out in China, the company said.
Apple Watch shipments in the U.S. have grown by more than 30% year on year to over 7.3 million units, Geneva estimates.
Geneva has been bullish on the Apple brand in Japan and its new product, but the company has faced pressure to rein in its supply chain, as it has a history of missteps in sourcing components for products.
In 2018, the U