The FDA is going negative on Plus.

The Food and Drug Administration has scolded Coca-Cola for placing inappropriate nutritional claims on its Diet Coke Plus soft drink.

They say it doesn't have enough nutrients to carry the word "Plus."

According to the agency, foods labeled "plus" must have at least 10 percent more nutrients than comparable products. The FDA also said it is inappropriate to add extra nutrients to "snack foods."

Federal health regulators issued a warning letter to the company, objecting to the product's labeling, which describes the drink as "Diet Coke with Vitamins and Minerals."

A Coca-Cola spokesman disputed the FDA's claims against Diet Coke Plus.

"This does not involve any health or safety issues, and we believe the label on Diet Coke Plus complies with FDA's policies and regulations," company spokesman Scott Williamson told Reuters.

The company has 15 days to outline plans to correct the violation. Williamson said the company plans to respond in early January.

Coca-Cola began selling Diet Coke Plus in April 2007. In a March 2007 press release from Coca-Cola, the company said that Diet Coke Plus "is a good source of vitamins B3, B6, and B12, and the minerals zinc and magnesium."

"Consumers, including Diet Coke drinkers, are increasingly looking for more beverage options, and we wanted to offer them the convenience of a calorie-free beverage that is a good source of several essential vitamins and minerals, and one that delivers on the great taste that they have come to expect from us," Katie Bayne, senior vice president, Coca-Cola Brands, Coca-Cola North America, said in a press release.

The company went on to say that each 8-ounce serving of Diet Coke Plus contains 15 percent of the daily required value for Niacin (vitamin B3), and vitamins B6 and B12, as well as 10 percent daily value for zinc and magnesium.

Click here to read more from Reuters.

The Associated Press contributed to this report.