US opposition to the pact remains unchanged, but "each nation will reach their own conclusions independently," spokesman Scott McClellan said, after Russia said it would not ratify the accord in its current form.

Asked about Moscow's decision, which dealt a severe blow to hopes for the agreement's ratification, McClellan replied: "It's not something that we have attempted to influence in any way in terms of other nations' decision-making."

President Vladimir Putin's top adviser on economic issues, Andrei Illarionov, said in Moscow Tuesday that "in its current form, the Kyoto Protocol places significant limitations on the economic growth of Russia."

His comments came as delegates from 180 countries met in Milan, Italy, to examine the future of the Kyoto accord, regarded by environmental protection groups as a key instrument in curbing global warming.

"Of course, in its present form, this protocol cannot be ratified," Illarionov said after Putin spoke to a gathering of Russian and European businessmen.

Asked whether Washington felt validated by the announcement, McClellan said US President George W. Bush had scrapped the protocol because it would cost the US economy millions of jobs billions of dollars.

"And as our economy is gathering steam, that's not the kind of approach we need to be taking for the American people," he said.

SPACE.WIRE