DAVOS, Switzerland (AP)--Brazil's foreign minister said Saturday that ethanol was the key to making trade work for the environment, a sensitive but increasingly important task amid rising concern over global warming.

In an interview with The Associated Press, Celso Amorim said Brazil would reject a U.S.-E.U. plan to open up trade in "eco-friendly" goods if the rules do not apply to his country's sugarcane-based ethanol.

Trade ministers said they would meet again in April to try to work out a new global commerce pact.

Ethanol "is the one single environmental good that has a proven effect in terms of climate change, and the reduction of CO2," Amorim told the AP. "If you want to have a development round, with an environmental dimension, and you exclude ethanol ... it's just to look good. It has no meaning."

The relationship between trade and the environment has become a hot-button issue for a number of countries, including the U.S., where Democrats in the U.S. Congress have forced the Bush administration to include environmental safeguards in trade deals.

The U.S. and the 27-nation European Union are urging members of the World Trade Organization to free solar panels, wind turbines and other products from tariffs, which they say would increase the use of climate-friendly technology around the world.

The plan, which excludes ethanol, is contingent on an agreement in the WTO's long-struggling effort to liberalize the global economy. The trade body's 151 members are struggling to remain engaged in a process that is in its seventh year and has missed countless deadlines but arguably has become more important now that the world appears set for economic slowdown.

"We have a window of opportunity, which has become a window of necessity," Amorim said.

For Brazil, which would reap billions of dollars in revenue from widespread ethanol liberalization, getting its fuel accepted as a cheap, eco-friendly alternative to fossil fuels has become a priority.

While business has boomed amid soaring oil prices and global warming concerns, the Latin American country says exports are still being held back by high U.S. and European tariffs. It notes that petroleum products, such as gasoline, face no tariffs.

Amorim rejected the concerns of some that so-called biofuel expansion may actually harm the environment through deforestation in countries like Brazil. Critics also have warned that a mass conversion of arable land into plantations for ethanol production could cause food shortages in poorer nations.

Sugarcane for ethanol amounts to less than 1% of Brazilian territory and 3% of its farm land, Amorim said. "So there is no problem."

The U.S. is the world's biggest ethanol producer, making its fuel primarily from corn, and President George W. Bush has made the fuel a central part of his plan to cut gasoline use by 20% by 2017. Brazil is second, but is the largest exporter.

Despite numerous logjams in the WTO trade round - including over ethanol - Amorim said he was somewhat more optimistic that an overall deal could be reached.

"If you ask me for anything concrete, it will be difficult for me to explain, but I feel there is now an attitude to find ways, to find an accommodation" so that a deal can be agreed, Amorim said. "Ministers need to decide either to conclude the round or give it a distinguished burial."