Robert F Kennedy Jr said he plans to tell the US national public health agency to stop recommending that fluoride be added to drinking water.
Fluoride is a naturally occurring mineral that has been added to water supplies since 1945 as it helps prevent tooth decay.
In 1999, the US Centers for Disease Control and Prevention (CDC) called water fluoridation one of the greatest public health interventions of the 20th century.
Since he was nominated as health secretary last year, RFK Jr has signalled he would recommend a ban on fluoride.
He has called the mineral a “dangerous neurotoxin” and claimed it poses other unproven risks to health.
Nearly two-thirds of the US population gets fluoridated drinking water, according to CDC data.
Calgary banned fluoride in 2011 due to its cost, but the Canadian city is currently reintroducing it into water supplies after a decade of deteriorating dental health.