As planned, iPhone sales have started via China Mobile, the largest carrier in China, today. The official iPhone China Mobile deal, which covers both the iPhone 5s and iPhone 5c, was announced in December. Earlier this week, Apple CEO Tim Cook promoted the event with multiple interviews, calling the partnership a “beginning.” Subsequent reports indicated that millions of iPhones have already been ordered through China Mobile…

To celebrate today’s launch, Cook and China Mobile Chairman Xi Guohua attended the opening at a China Mobile store. In celebration, Cook and the China Mobile executive offered autographed iPhone 5s and iPhone 5c units to the first customers to enter the store. Cook also took a few questions and made some statements at this opening.

Cook said, “today is just the beginning of China Mobile and Apple coming together to deliver the best experience in the world,” according to a report from Bloomberg News. Interestingly, Cook was asked if a bigger-screened iPhone is in the works. Unsurprisingly, Cook declined to comment much, solely saying, “We never talk about future things. We have great things we are working on but we want to keep them secret. That way you will be so much happier when you see it.”

Having fun in Beijing at the iPhone launch with China Mobile! pic.twitter.com/AqoqLbbeO7

— Tim Cook (@tim_cook) January 17, 2014

Apple has long been considering moving to a larger-screened iPhone, and numerous reports have indicated that Apple will likely launch said device in 2014. Apple has been testing iPhone screen sizes ranging from 4.5-inches, 4.7-inches, 5-inches, and all the way up to 6-inches.

Late last year, we reported that Tim Cook teased in a letter to employees that Apple has “big plans” for 2014.

Tim Cook autograph photo via Flickr