A spokeswoman for environment commissioner Stavros Dimas said the EU had not been in direct contact with the parties over the accord, but that she believed it did not set mandatory targets to reduce the gases that cause global warming.

"We are not very convinced that a voluntary agreement of this sort will have the significant impact which we need to combat climate change," said the spokeswoman, Barbara Helfferich.

She also said she believed the agreement, announced in Laos earlier on Thursday and focused on using clean technologies rather than coal, could not be seen as a substitute for the Kyoto climate change treaty.

"We believe, if that is the case, we have always supported clean technologies, but it can certainly not substitute for any commitment in terms of a Kyoto-like agreement," she said.

"The proof is in the pudding, what we need is to combat climate change."

In a "vision statement" issued on the sidelines of a regional forum in the Laos, the United States, Australia, India, China, South Korea and Japan announced their initiative on a non-binding compact to reduce emissions.

The new initiative does not have enforcement standards or a specific time-frame for signatories to cut emissions, unlike the 1997 Kyoto Protocol which the United States and Australia have refused to ratify.

Areas of cooperation envisioned range from the use of clean coal and nuclear power to that of wind and solar energy.

The six will also jointly develop technologies that "promote economic growth while enabling significant reductions in greenhouse gas intensities."