In January, Amazon announced the final 20 cities in the running to serve as home for its second headquarters, promising 50,000 new jobs and $5 billion in investment. Candidates include New York, Los Angeles and Washington, D.C.
As for Facebook, embroiled in a scandal over the potential misuse of user data by political firm Cambridge Analytica, Cook was asked what he would do if he were Mark Zuckerberg.
"I wouldn't be in the situation," he responded.
Cook also said Apple reviews apps in careful detail to confirm every app is meeting the privacy standards it has set for users.
"We don't subscribe to the view that you have to let everybody in that wants to, or if you don't, you don't believe in free speech," said Cook. "We don't believe that."