The Coca-Cola Co has replied to a complaint by the US Food and Drug Administration over its Diet Coke Plus drink.

The watchdog told Coca-Cola in December to remove the 'plus' from Diet Coke Plus, because the drink did not contain sufficient nutrient content to be marketed as a functional beverage.

It also said that adding functional ingredients to carbonated soft drinks is "not appropriate". FDA officials could ultimately force the firm to pull the drink if not renamed.

A Coca-Cola spokesperson told just-drinks today (16 January): "We have provided FDA with a response to their letter and look forward to discussing with them the points  they have raised."

She declined to give specific details of the response, but added: "We currently have no plans to change the labelling for Diet Coke Plus in the US."

Coca-Cola said late last month that the FDA complaint "does not involve any health or safety issues, and we believe the label on Diet Coke Plus complies with FDA's policies and regulations."