All EU nations must back proposals to cut harmful emissions by 30% by 2020 or risk jeopardising the global effort to curb climate change, warn ministers.
The call for unity among the 27-nation bloc was made by the UK Environment Secretary, David Miliband, and his Spanish and Slovenian counterparts.
Failure to act would threaten efforts to get nations such as the US and China to agree to cap emissions, they said.
EU environment ministers will discuss the proposals at a meeting on Tuesday.
In an article on the BBC News website, the ministers wrote: "We all know that the current Kyoto deal does not go far enough.
"If we are going to avoid the dangerous impacts of climate change... then the EU must stand up and lead the debate on committing to further action."
They called for all members to endorse the proposals outlined by the European Commission in its strategic energy review.
The review, published in January, called for an international commitment among developed nations to cut greenhouse gas emissions by 30% from 1990 levels by 2020.
Speaking at the time, Environment Commissioner Stavros Dimas said: "I urge the rest of the developed world to follow our lead, match our reductions and accelerate progress towards an international agreement on the global emission reductions."
However, international negotiations on the shape of the framework to replace the current Kyoto Protocol, which expires in 2012, have struggled to reach a consensus.
A number of nations have voiced doubts about the effectiveness of national emission limits.
In their article, David Miliband, Cristina Narbona and Janez Podobnik said that the EU had a "responsibility to demonstrate its leadership and commitment".
"Without such commitment, the global agreement we all need will slide further away from our grasp," they warned.
"The window of opportunity is closing rapidly and a strong EU voice is necessary to provide the catalyst for UN discussions on taking effective action to cut emissions."
The proposals will be discussed by the Environment Council in Brussels on Tuesday, before being considered for adoption by EU political leaders at an energy summit in March.