Uber Technologies says it will start offering users the choice of all-electric vehicles on its ride-hailing platform. It's part of the US firm's goal to reduce its carbon emissions to zero by 2040.

Uber says the service will start in more than 40 cities around the world. They include Los Angeles, New York, San Francisco and London. It will also be available in France and Australia.

The company's current "Uber Green" service includes hybrid models as well as EVs.

Uber CEO Dara Khosrowshahi said: "So at a time when people are backing away from an all-electric future, Uber is charging ahead."

He says EVs should be more affordable and stronger EV mandates are needed.