Robert F. Kennedy Jr., a prominent proponent of debunked public health claims whom Donald Trump has promised to put in charge of health initiatives, said that Trump would push to remove fluoride from drinking water on his first day in office if elected president, Associated Press reports.

Kennedy made the declaration on the social media platform X alongside a variety of claims about the heath effects of fluoride.

“On January 20, the Trump White House will advise all U.S. water systems to remove fluoride from public water,” Kennedy wrote. Trump and his wife, Melania Trump, “want to Make America Healthy Again,” he added, repeating a phrase Trump often uses and links to Kennedy.

Trump told NBC News that he had not spoken to Kennedy about fluoride yet, “but it sounds OK to me. You know it’s possible.”