Ecuador began drilling for oil on Sept. 7 near an Amazon rainforest nature reserve known as Yasuni, a site that President Rafael Correa had previously sought to protect from development and pollution under a pioneering conservation plan.

Correa in 2007 asked wealthy countries to donate $3.6 billion to offset revenue lost by not drilling in the Yasuni National Park. But the initiative was scrapped in 2013 after it brought in less than 4% of the amount requested.

Correa's government blamed the international community for the failure of a plan once seen as a possible model for other developing countries seeking to resist the lure of oil money.

Sept. 7's drilling by the state oil company Petroamazonas began in the ITT (Ishpingo-Tambococha-Tiputini) Block at Tiputini, which is just outside Yasuni. Ishpingo and Tambococha are within the Yasuni reserve itself.

The end of Ecuador's conservation initiative for the eastern Yasuni, a vast swath of rainforest on the equator, drew outrage from environmentalists when it was first announced.

"This is the worst imaginable place to be drilling for oil. The world can simply not afford to lose a place like Yasuni," said Kevin Koenig, Ecuador program director at Amazon Watch, in a statement.

About 1.67 billion barrels of oil lie under Yasuni's soil.

With output from the Tiputini Field, Ecuador's oil production will rise to about 570 Mbbl/d from a current level of about 550 Mbbl/d, government officials said.

Correra had said previously that drilling would affect less than 1% of the reserve.

"It's the start of a new era for Ecuadorean oil," said Vice President Jorge Glas after a tour of the site on Sept. 7.

"In this new era, first comes care for the environment and second, responsibility for the communities and the economy for the Ecuadorean people," he told reporters, adding that the cost of production was less than $12 per barrel (bbl).

Ecuador is OPEC's smallest member country and has suffered heavily from the decline in oil prices. Aboutd half its income comes from oil, according to the World Bank. It is also one of the world's most biodiverse nations, boasting Amazon rainforest, Andean mountains and the Galapagos Islands.