Tim Cook said it is a “privilege, not a problem” that the company’s sales are so reliant on its iPhone line, describing the smartphones as “the best market on earth”.

In the company’s most recent quarter, more than half of its revenue came from iPhone, and the unit is much, much bigger than any of its other activities (iPad, Mac, Services and Others). But with iPhone sales pressured, this has led to question marks over Apple’s longer term position.

In a wide ranging interview with The Washington Post, the CEO said that the industry is focused on a “90-day clock”, driven by quarterly reporting cycles. And while “the global economy’s not that great right now”, and the smartphone market is somewhat sluggish, for the long term there is plenty of opportunity.

Over time, every person in the world will have a smartphone, Cook said, while acknowledging that this will not be immediate – and certainly not all will be iPhones.

But he also said that technologies such as artificial intelligence will boost the usefulness of smartphones, and that there is no replacement device on the horizon in the short or medium terms.

The Washington Post also quizzed Cook on potential growth opportunities elsewhere in the business.

The executive iterated that Apple’s services business is set to be a Fortune 100 company in size next year, driven by products such as iCloud, App Store and Apple Pay. And regionally, India was mentioned, as operator investment in 4G was described as a “game changer”.

Enterprise and iPad Pro were also called out.