President Vladimir Putin had delivered this message to a gathering of European businessmen in Moscow on Tuesday, the official said, who asked to remain anonymous.

The warning came as representatives of 180 countries met in Milan, Italy, to discuss the pact, which cannot enter into force without Russia's agreement.

"This does not mean that Russia is refusing to ratify the Kyoto protocol. Quite the reverse, we are aiming to ratify the Kyoto protocol, but we do not want this document to be against Russia's interests," the official said.

"Because in its current form, it does not meet Russia's interests and effectively it means we must assume obligations which would hamper the country's economic growth," he added.

The Kremlin official said that Russia was negotiating to obtain its demands, and would not submit the pact to parliament for ratification if they were refused.

"Of course not, the president has said this quite clearly," he said.

Putin's adviser on economic issues, Andrei Illarionov, stunned European and other Western nations earlier this week by saying that Moscow did not see any economic grounds for ratifying the protocol it signed in 1997.

He was contradicted a day later by the country's deputy trade and economic development minister, who insisted that Russia was "moving towards ratification," but flatly dismissed those comments.

Since the United States, the world's biggest polluter, abruptly withdrew from the pact limiting greenhouse gas emissions in 2000, Russia's participation has become an essential cornerstone of the agreement.

But Illarionov said Tuesday that "in its current form, the Kyoto Protocol places significant limitations on the economic growth of Russia, adding: "Of course, in its present form, this protocol cannot be ratified."

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

Russia, which is the world's third-largest polluter after the United States and China, in theory stands to be a major beneficiary from the accord.

The cash-strapped country already emits a third less carbon dioxide than it did a decade ago because of the decline of its heavy industry, giving it emission permits that it can sell to Western countries.

But since indicating at a world summit in Johannesburg last year that it would probably ratify the deal, Moscow has cooled on the topic.

Illarionov says the agreement would limit Russia's economic potential at a time when its economy is roaring ahead at nearly seven percent a year.

It committed 38 industrialised countries to an overall cut of 5.2 percent of carbon-rich gases, mainly the by-product of burning oil, gas and coal, by 2010 compared with their 1990 levels.

Russian officials also say that the loss of the massive US market for selling emission credits mean that they have only Europe and Japan as potential customers.

"We could make three billion dollars a year from trading emissions credits, but who is going to buy them from us?" the Vedomosti business daily quoted an unnnamed official in the trade and economic development ministry as saying.

The European Union has played down Russia's doubts but British weekly The Economist this week accused Moscow of using its bargaining clout to get more money.

"Russia is trying to blackmail the European Union, which is desperate for the treaty to come into force, into promising investment guarantees, favourable prices for exports of Russian natural gas or other economic goodies. In short, Russia is using the threat of pulling out as a bargaining chip," it wrote.

SPACE.WIRE