At a speech in the West Midlands, the Prime Minister pledged to help car makers prepare for a pollution-free future which would be spearheaded by Britain.
She also announced £106 million in funding for research and development in green vehicles, new batteries and low carbon technology in the West Midlands.
Britain is to ban the sale of new petrol or diesel cars from 2040, by which time zero-pollution vehicles such as electric cars – which are currently being piloted in the West Midlands – will be sold instead.
Mrs May's announcement came as Birmingham considers introducing a controversial 'clean air' charge, which could see motorists face a £10 fee for driving within the city's ring road. The plans have met with widespread public criticism.
The Prime Minister was addressing delegates at the world's first zero emission vehicle summit at Birmingham's ICC.
She said: "I want to see Britain, once again, leading from the front and working with industries and countries around the world to spearhead change.
"That is why I have set this country an ambitious mission. To put the UK at the forefront of the design and manufacturing of zero emission vehicles and for all new cars and vans to be effectively zero emission by 2040.
"Already we are taking significant strides forward. Our electric UK manufactured cars account for one in five sold in Europe. Our batteries are among the best in the world.
"And our Road to Zero Strategy is the most comprehensive plan globally - mapping out in detail how we will reach our target for all new cars and vans to be effectively zero emission by 2040 - and for every car and van to be zero emission by 2050."
Mrs May also highlighted investment in green vehicle technology from private firms, saying that £500m had come from key industries in the sector to add to a £100m funding pot from the Government.
She said that both cash injections will 'drive the design, use, uptake and infrastructure necessary for cleaner, greener vehicles' – and help the UK meet its obligation to the Paris climate accord.
Home of car making
West Midlands Mayor Andy Street said: "The West Midlands is already the home of UK automotive manufacturing."
He added: "Names like Jaguar Land Rover and Geeley proudly call the West Midlands home and are market leaders who continue to invest in our region, drawn by the strong skills base, healthy supply chain and world-class R&D.
"It is absolutely vital we continue to build on this as we move towards future automotive technologies, low-emission vehicles and driverless vehicles.
"Two particular game-changing developments will particularly help us to develop these new industries.
"The first is the £100m battery institute at the University of Warwick which will cement our region as the centre of this technology.
"And the second is the successful bid to be the home of the 5g testbed announced last week and is absolutely imperative for the development and roll-out of connected and autonomous vehicles.
“The future is happening. We are trialling autonomous vehicles on our region’s roads already and our universities and R&D centres are working with the private sector to drive down emissions and develop technology, supporting sectors which will create the jobs of the future here in the West Midlands."
The Government has viewed the summit as an opportunity to try to drive more foreign investment into the UK through discussions on how to accelerate the development of the zero-emissions market.
She was due to hold talks with supply-chain companies from the US, Germany, Japan, China, Spain and India during the event, which will also see the unveiling of a UK-led international initiative dubbed the 'Birmingham deceleration'.
The project aims to pave the way for the global deployment of green vehicles and the introduction of zero-emission infrastructure, with its first signatories including Italy, France, Denmark, UAE, Portugal, Belarus and Indonesia.
Also speaking at the summit, Business Secretary Greg Clark announced that taxpayers would contribute to rolling out a network of charging stations for electric vehicles.
He said this would enable drivers to charge up their cars on motorways 'in minutes'.
Mr Clark also made the case for a Brexit deal along the lines of Mrs May's much-criticised Chequers proposals, due to the importance of EU trading ties for car manufacturers.
He added: "It's one of the reasons why we need to have a deal with the rest of the EU that allows one of the most sophisticated ways of producing products on earth – the components coming in from all parts of the EU and elsewhere across the world, and being exported out there."