Automakers selling cars in the EU may face tougher CO2 emissions reduction targets after the European Commission signaled it will review goals already set for 2030.

The Commission will propose to revise by June 2021 legislation on CO2 emissions standards for cars and vans "to ensure a clear pathway from 2025 onward toward zero-emissions mobility," it said in a document called the European Green Deal.

In April, the European Union passed legislation that mandates automakers selling cars in Europe to cut their average fleet CO2 emissions by 37.5 percent by 2030 to 60 grams per kilometer relative to a 2021 baseline of 95g/km. In 2018, emissions from new cars increased for the consecutive second year, rising to 120.4g/km.

The new European Commission presented its long-term roadmap for a climate neutral EU economy on Wednesday. Commission President Ursula von der Leyen has put climate action at the top of her legislative agenda for the next five years.

"The Commission is within its mandate to propose a new target, but any such step would come with the requisite economic impact assessment and require approval from the EU Parliament and EU Council to enter into legislation,” a Commission spokeswoman said.

She declined to comment on whether a 15 percent intermediate CO2 emissions reduction target for 2025 could also be reviewed.

The emissions reduction targets are part of the EU's commitment to tackle climate change by moving to carbon neutrality by 2050. As a result, it is not uncommon for Brussels to re-evaluate whether targets were proving effective for achieving policy goals, and adjust them where necessary, the spokeswoman said.

The guidelines will push automakers to invest even more heavily in in electric cars to avoid fines from the EU for missing targets. Sales of full-electric and plug-in hybrid cars are expected to grow 35 percent in the first nine months of 2020, a rate far higher than China and North America, according to BloombergNEF.

The Commission said it would consider including road transport in the European emissions trading scheme (ETS) already used by energy-intensive industries such as utilities, and steel and cement producers as a further tool to reduce CO2 output.

Road transport accounts for one fifth of the EU's total greenhouse gas emissions and its CO2 footprint has grown since 2014, according to the most recent data from the European Environmental Agency.