In his first political comment in months, ailing Cuban leader Fidel Castro broke his silence in a newspaper column Thursday to heap scorn on U.S. President George W. Bush's "sinister" environmental policies.

The article was published in the state-run Granma daily, under the headline: "Condemned to premature death by hunger and thirst more than three million people of the world."

Although there was no mention of Castro's health, the letter nevertheless fuelled speculation the 80-year-old, who has been recovering from intestinal surgery, was moving to reassert his voice in world affairs and return to the presidency.

Castro signed the letter and is believed to be the author, as it was written in the same apocalyptic tone he is known to take when criticizing the U.S. impact on developing countries.

"The sinister idea of converting food into combustibles was definitively established as the economic line of the foreign policy of the United States," the letter reads.

His article opposes developing biofuels and asserts that millions of people in the Third World would starve if rich countries began importing huge amounts of traditional food crops such as corn in order to harness ethanol.

"Apply this recipe to the countries of the Third World and you will see how many people among the hungry masses of our planet will no longer consume corn," the article said. "Or even worse: By offering financing to poor countries to produce ethanol from corn or any other kind of food, no tree will be left to defend humanity from climate change."

Castro's condition and the exact ailment are state secrets. He announced July 31 he had undergone surgery and turned power over to his 75-year-old brother, Raul. Last month, Castro appeared in a live radio broadcast for the first time since falling ill.

With files from the Associated Press