Tim Cook, CEO of Apple, played down concern that the success of the iPhone is reaching its limits, stating that “we don’t have that word in Apple’s vocabulary”.

Speaking at the Goldman Sachs Technology and Internet Conference this week, Cook highlighted the “momentum” seen by its flagship smartphone, noting that there is still growth in the global market for it to exploit.

The executive said that currently, the iPhone is “really only available to about 50 percent of the subscribers in the world,” arguing that there is a “huge opportunity” to grow this. He also highlighted the company’s strong performance in growing its business in China, stating that “I think it’s hard for anyone to look at that and say it’s not impressive”.

Unsurprisingly, Cook would not be drawn on whether Apple is planning a low cost version of the iPhone, although he did note that the company has already “made moves to make things more affordable”.

He said that when it lowered the price of the iPhone 4 and iPhone 4S following the launch of the iPhone 5, “it surprised us as to the level of demand we had” – in the December quarter, the company did not have enough supply of the iPhone 4.

When asked about the potential to offer an iPhone with a larger display, Cook said that “some people are focused on size, but there are other things that matter”. Arguing that the retina display on the iPhone is “twice as bright” as the OLED screens used by rivals, Cook said that “the customer experience is always broader than that which can be defined by a single number”.

“Do you know the speed of an Ax processor? You probably don’t. But does it really matter?” he observed.

Cook also said that apple has a “significant lead” in the tablet market, a sector he believes will be “huge”. Apple has a package of hardware, software and services that “create an experience that is jaw-dropping”, he argued, noting that “we worked really hard on our ecosystem”.

Responding to the assertion that the iPad mini could impact sales of premium-priced iPad devices, Cook argued that “our basic belief is that if we don’t cannibalise, someone else will”.

Noting that the Windows PC sector has more to lose than Apple, Cook said: “It seems perfectly reasonable to me to have an iPad and iPad mini. I would argue that it probably wouldn’t be smart not to”.

He also said that in some markets, 50 percent of iPad customers do not own another Apple product before making their purchase, bringing a new customer into the fold.