SAN FRANCISCO — With the introduction of a cheaper iPhone on Tuesday, Apple took a step toward catering to China, the world’s largest smartphone market and one that is crucial to the company’s future.

But the cost of the phone — more than $700 in China — will still keep Apple’s phones beyond the reach of most Chinese consumers. And that predicament only underscores what has become increasingly clear in recent months: that Apple’s fortunes in China largely depend not on any phone, but on reaching a deal with China Mobile, the country’s largest cellphone carrier.

On Wednesday, Apple took another step in that partnership, when the Chinese government said that Apple’s phones could run on China Mobile’s new cell network, essentially paving the way for a deal between the companies.

An agreement would instantly give Apple access to China Mobile’s 700 million customers, and reaching it might require Apple to bend on price. China Mobile has been holding out on a deal for years, and it is now positioned to ask for better terms with Apple.