May 12 (UPI) -- Food and Drug Administration Commissioner Marty Makary has left the administration after 13 months at that post, President Donald Trump confirmed Tuesday.

Makary is leaving the helm of the federal agency that is largely responsible for regulating medical treatments and vaccines, as well as overseeing safety the country's food supply, the president said.

Trump declined to say whether Makary was fired or had resigned, but acknowledged that he had been facing criticism.

Makary "was having some difficulty," Trump told reporters in Washington as he was embarking on a trip to China.

Related