Countries around the world need to act with a sense of urgency if the 2015 UN climate change talks on cutting emissions are to have a credible outcome, a top EU official warned Friday.

EU climate commissioner Connie Hedegaard said rich and poor nations alike should be prepared to commit to legally binding commitments limiting planetary warming to 2 degrees Celsius (3.6 Fahrenheit) over pre-industrial levels.

Negotiators have set a 2015 deadline for signing in Paris the UN's most ambitious environmental deal that for the first time would bind all the world's nations to measurable targets for curbing Earth-warming greenhouse-gas emissions by 2020.

"This 2015 deadline should be taken seriously and it should come up with some substantial outcome," Hedegaard told reporters during a one-day visit to the Philippines.

She noted that there had been less urgency in dealing with climate change going into the talks as economic crises in Europe and the West had distracted many economies.

"Although many of us share some sense of frustration (about) how things are moving forward too slowly, frustration does not reduce emissions, concrete actions do," she said.

Asked whether she was optimistic about the prospects of legally binding commitments by 2015, Hedegaard said governments must put faith in the process.

"If there is to be credibility around the multilateral process, then it must also deliver on its 2015 deadline," she said.

She said all countries must be "equally legally obliged to do the best we can, according to our capabilities."

However, she said the EU also realistically believed that developed countries that pollute "must do more of the job than the less developed".

The target of limiting planetary warming was formally adopted at a UN climate conference in Copenhagen in 2009, and remains the aim for negotiators drafting a new, global pact that must enter into force in 2020.

Negotiations are to meet in Paris in 2015 where they are tasked with coming up with an ambitious deal in which all the world's nations will be bound to measurable targets in curbing greenhouse gas emissions.