The EU has passed a law to ban sales of new CO2-emitting cars from 2035, effectively outlawing new diesel and petrol engines. Tighter CO2 limits for carmakers' fleets also take effect next year.
Italy and the Czech Republic have said that slumping electric car sales mean carmakers cannot meet these targets, and asked Brussels to urgently review them.
Asked by EU lawmakers about his plans for the auto sector, climate commissioner Wopke Hoekstra said the climate rules provided a predictable investment environment.
The European Commission has already agreed to tweak its 2035 phase-out date to allow cars running on e-fuels to be sold after the deadline, at Germany's request.
Automakers have warned they cannot meet next year's EU car CO2 limits and are bracing for potentially billions of euros in fines.
Hoekstra said those fears may be overstated, given the relatively low fines carmakers faced for missing 2020 EU emissions targets. Volkswagen faced penalties exceeding 100 million euros.
