A number of countries, led by Italy, had expressed concern at the target of reducing the 27-nation bloc's emissions by 90 percent from 1990 levels by 2040.

The final deal allows for five percent of cuts to be accounted for through carbon credits acquired for projects outside Europe. Activist groups have accused the EU of simply sending the climate change campaign offshore.

Further down the road, the EU could if needed eventually allow member states to make up a further five percent of their targets via credits from international carbon markets.

Under pressure from Poland and Hungary, the deal also put back by one year to 2028 an emissions trading system for road transport and heating buildings.

Behind only China, the United States and India in terms of emissions, the EU has been the most committed of the major polluters to climate action and has already cut emissions by 37 percent compared to 1990 levels.

The deal still has to be given formal approval by the 27 EU states and by the EU parliament.