Apple is expected to announce this week that it has sold more iPhones in China than in the US for the first time in 2014, highlighting the shifting balance of power in the smartphone market. Analysts at UBS estimate that China accounted for 36% of iPhone shipments in the most recent quarter, compared with 24% for the US. During the same period last year, 29% of units were sold in the US and 22% were in China, UBS said. The push into China is huge, as the US market becomes saturated and iPhone growth slows.

Apple has been steadily ramping up its efforts in China over the last few years. In December 2013, Apple was able to strike a deal with China Mobile — the largest network operator in China that has more subscribers than Verizon, AT&T and Sprint combined — to sell the iPhone 5s, and now the iPhone 6 and 6 Plus. Apple accepted Chinese demands for a full security inspection of its products to ensure that it can continue selling its hardware in the country last week, over Chinese government concerns Apple could covertly spy on its citizens through its US-designed hardware and software.

Apple opened a new store in Hangzhou, China on Saturday, the first of five shops planned to open ahead of Chinese New Year on February 19. Earlier this month, a store opened in Zhengzhou, with three more opening in the coming weeks. Zhengzhou and Hangzhou have populations in the millions. The new stores are part of Tim Cook’s push to expand Apple’s presence in China, one of the largest markets for Apple products in the world. Cook said in 2014 that he wanted to open 25 Apple Stores in China over the next two years.