Ecuador has abandoned a pioneering conservation plan in the Amazon that attempted to raise funds from the international community instead of drilling for oil in a pristine corner of the Yasuni national park.

The collapse of the Yasuni ITT initiative is a devastating blow for activists who are trying to save one of the world's most biodiverse regions from development and pollution. It also kills climate campaigners' hopes that the Ecuador plan could provide a model for other nations to resist the lure of oil money and leave fossil fuels under the ground.

President Rafael Correa blamed the failure on the lack of foreign support, after a trust fund set up to manage the initiative received only $13m (£8.3m) in deposits, a tiny fraction of the $3.6bn goal.

"The world has failed us," Correa said in a televised address on Thursday night. "I have signed the executive decree for the liquidation of the Yasuni-ITT trust fund and with this, ended the initiative."