Apple’s plan to ramp up iPhone production by 10% in the first half of this year may face difficulties as the coronavirus outbreak that has gripped China.

The Nikkei Asian Review reported on Tuesday that Apple has asked its suppliers, many of whom have manufacturing centers in China, to make up to 80 million iPhones in the first half of 2020. The orders included 65 million units fir the existing iPhone models and 15 million units for the new chaper iPhone, the successor to the iPhone SE, set to be unveiled in March, according to the report.

However, the mass production which is due to start in the third week of February might be delayed due to the virus outbreak, the Nikkei reported.

Virtually all of the world’s iPhones are made in China, primarily by Foxconn’s Hon Hai Precision Industry Co. at its so-called iPhone City in Zhengzhou and by Pegatron Corp. at an assembly site near Shanghai. Each of those locations is more than 500 kilometers away from Wuhan in central China, the epicenter of the viral outbreak, but that distance doesn’t immunize them from its effects.

The coronavirus outbreak has so far killed more than 100 people and infected over 4,500 in China.

Apple's supply chain also has a few million workers manufacturing products like the iPad, iPhone and Apple Watch. Many of those employees have been home the past few days for the holiday, and the company hasn’t said if it is asking them to stay home for longer to prevent the virus spreading. Chinese authorities have imposed severe travel restrictions and taken the drastic step of quarantining the entire city of Wuhan, a population of more than 11 million.

Apple did not respond to a request for comment. However, investors and analysts will be looking to Chief Executive Officer Tim Cook to make comments on the virus and its impact on Apple during Tuesday’s conference call to discuss the latest quarterly financial results.