Speaking to host Fareed Zakaria in an interview on the Global Public Sphere programme, Akerson’s comments retract the predicted 2015 roll out GM had publicised earlier this year. However, he said, progress was being made and the technology is becoming more viable.

‘We're looking at hydrogen fuel cells which have no carbon emissions. Zero,’ he said. ‘They're very expensive now, but we've just in the last two years reduced the price of that technology by $100,000.

‘The car is still too expensive and probably wouldn't be practical till the 2020-plus period. I don't know.  And then there's the issue of infrastructure.’

To watch the interview in full, visit the CNN website here.