NEW YORK (Reuters) -U.S. Health Secretary Robert F. Kennedy Jr. told food companies including PepsiCo ( PEP ) and Kraft Heinz ( KHC ) in a meeting on Monday that the Trump administration wants artificial dyes out of the food supply before Kennedy leaves office, according to an email seen by Reuters.

Kennedy has pledged to tackle chronic illnesses by overhauling the U.S. diet. He has encouraged fast-food chains to switch to beef tallow instead of seed oils for French fries, and pushed for bans on additives like food colors.

The U.S. Food and Drug Administration, part of the agency Kennedy oversees, plans to work with the industry to create a federal framework on food dyes, according to the email, sent by the Consumer Brands Association, a trade group representing PepsiCo ( PEP ), Kraft Heinz ( KHC ) and other food and consumer goods makers.

California last year banned dyes from food served in school lunches, and Virginia and New York State are considering similar measures.

Bloomberg News first reported on the discussion between Kennedy and the food companies.

According to the email, the FDA wants to "avoid state patchworks," or many states making their own laws on the topic, which could create confusion and hurdles for global companies.

Kennedy "expects 'real and transformative' change by 'getting the worst ingredients out' of food," according to the email. He also made clear that he will "take action unless the industry is willing to be proactive with solutions," the email states.

Consumer Brands Association CEO Melissa Hockstad said in a statement that the group looks forward to continuing to work with Kennedy.

A PepsiCo ( PEP ) spokesperson said the Cheetos-maker was focused on "providing consumers with convenient, affordable and safe foods and drinks - including more options with natural ingredients, no synthetic colors and reductions in sugar, fat, and sodium."

Kraft-Heinz ( KHC ) did not respond to a request for comment.