Coca-Cola, under pressure from environmentalists over its packaging policies, has pledged to use reusable containers for at least 25 per cent of its beverages by 2030.

The soda giant announced the pledge Thursday, saying it would be implemented globally through the glass and plastic bottles it sells to consumers and through the containers used at soda fountains and dispensers.

Refillable containers accounted for about 16 per cent of total volumes in 2020, Coca-Cola said.

"Reusable packaging is among the most effective ways to reduce waste, use fewer resources and lower our carbon footprint in support of a circular economy," said Ben Jordan, senior director of packaging and climate at Coca-Cola.

But the coalition #Breakfreefromplastics, which has rated the company the world's top plastic polluter because of its historic use of single-use plastic containers, offered only measured praise.

"Coke's announcement that they are expanding their reusable packaging target globally is definitely a step in the right direction," said Emma Priestland, global corporate campaigns coordinator for the group.

"The company's string of broken promises in the past, however, compels us to welcome this announcement with some skepticism."

The advocacy group As You Sow, which has drafted a shareholder proposal urging greater use of refillable bottles, praised the announcement.

Conrad MacKerron, the group's senior vice president, said he was "pleased" by Coca-Cola's commitment, adding that, "this action has the potential to substantially reduce the amount of single-use plastic bottles used, many of which end up as ocean plastic pollution."

As You Sow said it will undertake additional analysis of the pledge to determine whether to withdraw its shareholder proposal.