“I want to thank Dr. Marty Makary for having done a great job at the FDA,” President Donald Trump, who multiple outlets reported had approved a plan to fire Makary, announced in a post on Truth Social on Tuesday. “So much was accomplished under his leadership. He was a hard worker, who was respected by all, and will go on to have an outstanding career in Medicine.”

Trump also confirmed that the FDA’s Deputy Commissioner for Food Kyle Diamantas, who the President called “a very talented person,” will replace Makary and serve as the agency’s acting head. 

“He’s a great doctor, and he was having some difficulty,” Trump said of Makary while speaking to reporters outside the White House on Tuesday. “But he’s going to go on and he’s going to do well.” 

Makary’s departure comes after the FDA last week announced its first approval of fruit-flavored e-cigarettes, a significant shift in the agency’s policy that has drawn criticism from health groups.

Makary reportedly clashed with Trump and others in the Administration over the decision to give that authorization, which he opposed. His concern over the move, due to such vapes’ appeal to young people, was what ultimately prompted Makary’s decision to resign, The New York Times reported, citing people familiar with the matter. 

The contention surrounding the decision was the latest in a series of controversies during Makary’s tenure at the FDA, which was marked by upheaval at the agency as it underwent mass layoffs and many senior career officials resigned or were forced out, as well as by tensions with industry and advocacy groups over drug reviews and approvals.

In addition to the reported internal dispute over e-cigarettes, Makary was also the subject of growing anger from outside allies of the Administration in the lead-up to his departure, including anti-abortion groups, which have accused him of dragging out a review of the abortion pill mifepristone.

Pharmaceutical industry executives, meanwhile, have raised complaints about a lack of consistency in the FDA’s reviews of their products under Makary’s leadership, even as he sought to streamline the review process. Makary also came under fire from public health leaders, who accused him of catering to anti-vaccine activists.

Secretary of Health and Human Services Robert F. Kennedy Jr., who had also reportedly grown frustrated with how Makary was leading the agency, praised the outgoing FDA chief in a post on social media on Tuesday. 

“Marty, you took on entrenched interests, challenged the status quo, and never lost sight of the American people we serve,” Kennedy wrote. “You pushed forward critical reforms and helped advance our mission to Make America Healthy Again. I’m grateful for your courage and your friendship. Wishing you the very best in your next chapter.”

The HHS Secretary added that “the search for a new Commissioner is already underway.”