As many as 1.5 million children are working on cocoa farms in the Ivory Coast and Ghana, the world's top two producers, despite more than 10 years of efforts to reduce child labor, the International Labor Rights Forum (ILRF) said in a report.

The report, released on Wednesday, highlights how far the cocoa and chocolate industry still has to go to meet global standards as consumers increasingly demand that the production of cocoa, the main ingredient in chocolate, not include child labor.

"After more than a decade of effort to reduce child labor on cocoa farms in West Africa, child trafficking continues to plague the region," the report stated.

Concern about a supply deficit by 2020, due to falling yields and rising demand, caused chocolate companies such as Barry Callebaut, Mars Incorporated, Mondelez International and Hershey Co. to increase their sustainability efforts to ensure long-term supplies.

They are spending millions of dollars to help improve cocoa farmers' lives by educating them on improving farm productivity, building schools and certifying their beans, but these efforts do not always target poverty, the root cause of child labor, the ILRF said.