Starbucks, the world's biggest coffee chain, has reversed its policy of allowing people to use its cafes in North America even if they have not bought anything.

BBC News reports that the changes, which are set to come into force from 27 January, constitute a U-turn from its policy, introduced six years ago, by which people could stay as long as they wanted, and even use their toilets, without making a purchase.

The move is part of the "back to Starbucks" strategy — a plan announced by the firm's new CEO, Brian Niccol, who previously headed the Mexican food chain Chipotle. The company had been experiencing diminishing sales because of a backlash to price increases and boycotts sparked by the Israel-Gaza war.

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The company said the new rules will be displayed at every store and staff will be instructed to ask anyone who violates the code of conduct to leave. That includes allowing employees to call the police when necessary.

Starbucks said the policy change only applied to its North America stores, which number more than 17,000.