Apple Inc CEO Tim Cook said that factories in China that manufacture the US tech giant's products are reopening, with the senior executives saying that "China is getting the coronavirus under control".

The comments came after Apple had already reopened a string of retail stores in China which had been temporarily closed amid the epidemic.

Cook said in an interview with Fox Business that "I am very optimistic there", with the numbers of confirmed cases of the novel coronavirus infections in China coming down day by day.

"On the supplier side, we have suppliers — you know, iPhone is built everywhere in the world. We have key components coming from the United States, we have key parts that are in China, and so on and so forth," Cook said.

"When you look at the parts that are done in China, we have reopened factories, so the factories were able to work through the conditions to reopen. They're reopening. They're also en-ramp, and so I think of this as sort of the third phase of getting back to normal," the senior executive added.

Apple announced on Feb 20 that it had reopened 10 Apple stores in China. It came just days after the US tech giant reopened five Apple stores in Beijing on Feb 14.

Cook said in a post on the social networking platform Weibo earlier this month that "As we welcome back employees and customers, and work alongside our manufacturing partners to resume operations as safely and steadily as possible, we are holding fast to our commitment to the many communities we're a part of in China."

"Apple is contributing to their efforts by doubling our donations to support immediate relief work as well as longer-term communitywide recovery. We are with you," Cook added.