The cuts are relative to 1990 levels. The EU's emissions since then are already down by almost 20 percent.
The EU is the second party to submit a climate target to the U.N., after Switzerland. Only a handful of other countries are expected to meet an end-of-March deadline to submit targets.
Others, including India and China are likely going to need more time. All countries are supposed to present targets for a new global climate agreement that governments plan to adopt in Paris in December.
The deal would be the first time that all countries take joint action to reduce global emissions of greenhouse gas emissions, which scientists say are a key driver of global warming.
Some climate activists said the EU's emissions target wasn't ambitious enough and criticized the bloc for not including any financial commitments to help developing countries cope with climate change.
Financing is a crucial issue in the U.N. climate talks. Developed countries have pledged to collectively come up with $100 billion a year in climate finance by 2020, but they are reluctant to specify their individual long-term contributions.
Still, many see the EU — one of the few parties that want the emissions targets to be legally binding — as a leader in the climate talks.
"Their commitment reflects a spirit of transparency that is a model for other countries," said Jennifer Morgan of the Washington-based World Resources Institute. "We expect the EU and other countries to look for ways to strengthen their actions in the lead up to a strong, universal climate agreement in Paris."