Fander Falconi was the third government official to resign over a plan to seek international donations of $3 billion over the next 10 years to keep an estimated 850 million barrels of heavy crude oil under the ground in the remote Yasuni National Park.

Prospective donors have demanded some control over how the money is spent and asked Ecuador to expand the amount of land protected from development under the initiative.

Correa blasted them Saturday, calling their conditions an ''unacceptable'' and ''embarrassing'' affront to Ecuador's sovereignty.

''If they don't accept our conditions, they can keep their money and we'll drill,'' Correa said in his weekly radio address.

Two members of a three-man government committee appointed to oversee the Yasuni fund resigned on Monday over the comments, followed by Falconi on Tuesday.

A foreign ministry statement did not say why Falconi resigned, but two ministry officials told the Associated Press that he, too, quit over Correa's criticism of the Yasuni negotiations. The officials spoke on condition of anonymity as they were not authorized to give information on the subject.

The proposal is more than two years old and has no confirmed donors, but the idea seemed to be gaining traction ahead of December's climate change summit in Copenhagen. Environmentalists say it could set a precedent in the fight against global warming by lowering the high cost to poor countries of going green.

Spain gave Ecuador $200,000 to help set up an international trust fund last year and by December, Ecuador's government said, Spain, Germany, Belgium, France and Sweden had offered to cover nearly half the $3 billion.

But the talks never led to a firm cash commitment.

The proposal would block drilling in three oil fields in Yasuni, but it does not explicitly prohibit development in the rest of the park. It was declared a biosphere reserve by the United Nations and is home to Amazon Indian tribes living in voluntary isolation.

Correa has set a June deadline for the initiative.

Ecuador is an OPEC member that depends on oil for a third of its national budget. The three oil fields in Yasuni represent 20 percent of its crude oil reserves.

Falconi is one of the founders of Correa's Alianza Pais party. He served for more than two years as Correa's third foreign minister.