Six major automakers on Wednesday will commit to phasing out the production of fossil-fuel vehicles around the world by 2040, as part of global efforts to cut carbon emissions, Britain said in a statement.
But sources familiar with the pledge's contents said some big carmakers including the world's top two, Toyota Motor Corp and Volkswagen AG, and crucial car markets China, the United States and Germany have not signed up. This highlighted the challenges that remain to shifting to a zero-emission future.
Sweden's Volvo, U.S. automakers Ford and General Motors, Daimler AG's Mercedes-Benz, China's BYD and Jaguar Land Rover, a unit of India's Tata Motors, were set to sign the pledge at climate talks in Glasgow, the latest initiative to help cap global warming by mid-century.
Volvo has already committed to going fully electric by 2030.
Britain, which is hosting the COP26 summit, said four new countries including New Zealand and Poland were joining other nations already committed to ensuring all new cars and vans are zero emission by 2040 or earlier.
The statement comes on a day dedicated to transport at the conference.
But the apparent unwillingness of China, the world's largest car market, and the United States - the world's largest economy and second-largest car market - to join the pledge raises questions about its effectiveness.
Sources said while the United States is not joining the pledge, key car-buying states like California and New York have signed up.
An auto industry source said some carmakers are wary of the pledge because it commits them to a costly shift in technology, but lacks a similar commitment from governments to ensure the necessary charging and grid infrastructure would be built to support electric vehicles.
In the summer the European Commission proposed an effective ban on fossil-fuel vehicles by 2035, accompanied by a commitment to charging infrastructure that carmakers had demanded.The world's No. 4 carmaker, Stellantis, was also missing from the latest pledge, as were Japanese carmakers Honda and Nissan; Germany's BMW and Korea's Hyundai.
According to sources, ride-hailing company Uber will also be a signatory.
The British government statement said a joint declaration would also be signed by companies including food retailer Sainsbury's and cities around the world aiming to green their vehicle fleets.
Cars, trucks, ships, buses and planes account for around a quarter of all global carbon emissions, data from the International Energy Agency showed, of which the bulk comes from road vehicles.
 "6 major carmakers agree to phase out fossil-fuel vehicles by 2040, UK says")
