Apple announced a major partnership with China UnionPay to put is digital wallet to work in the world's most populous country.

China UnionPay customers will be able to add their bank cards to Apple Pay on iPhones, iPads, or Apple Watch wearables, the companies said in a joint statement.

"China is an extremely important market for Apple and with China UnionPay and support from 15 of China's leading banks, users will soon have a convenient, private and secure payment experience," said Apple senior vice president of software and services Eddy Cue.

The service could be available early next year, pending approval of Chinese regulators.

Apple touts its digital wallet as letting people make purchases easily and securely, encrypting and hiding away personal data to thwart thieves.

UnionPay operates China's national inter-bank clearing and settlement system and reported having issued more than five billion cards to date.

Apple launched its digital wallet last year in a move capitalizing on the popularity of its mobile devices and taking on rivals such as Google and PayPal, which are also competing in the market.