Daily SumUp

US Health Secretary Robert F Kennedy Jr has pledged "a massive testing and research effort" to determine the cause of autism in five months.

Experts cautioned that finding the causes of autism spectrum disorder – a complex syndrome that has been studied for decades – will not be straightforward, and called the effort misguided and unrealistic.

Kennedy, who has promoted debunked theories suggesting autism is linked to vaccines, said during a cabinet meeting on Thursday that a US research effort will "involve hundreds of scientists from around the world."

"By September, we will know what has caused the autism epidemic and we'll be able to eliminate those exposures," Kennedy said.