"We spend quite a bit of time in training our suppliers to have the necessary expertise," Jackson added.

Apple is also looking to help power its suppliers with renewable energy. "We are building an additional 200 megawatts of new solar power projects in China, with 170 megawatts now under construction in Inner Mongolia," Jackson said.

Foxconn, one of Apple's top suppliers, is building 400 megawatts of solar power projects in Henan province to generate as much clean energy as its Zhengzhou factory consumes in final production of the iPhone, which is expected to be completed by 2018, she said.

Apple saw its first 40-megawatt solar power project in China completed in October last year, which is generating enough energy to power all of Apple's 19 offices and 31 retail stores in China, including four stores in Hong Kong.

"As Apple's facilities in China use 100 percent renewable energy, all the new clean energy that comes online is for our suppliers," Jackson said.

"We've committed to a total of two gigawatts of new clean energy. We still have 1,400 megawatts to go and we are working on a number of projects across China," she added.

The company is also working with the World Wildlife Fund to create and preserve six million mu (400,000 hectares) of sustainable forest in Hunan, Yunnan, Fujian, Guangdong provinces and Guangxi Zhuang Autonomous Region.

"The idea is to create jobs in the sustainable paper making industry," Jackson said, "We could buy our paper from China instead of somewhere else for packaging."

"We've been very busy on the environmental front, because it's one of our core values," she said.