Food and Drug Administration Commissioner Dr. Marty Makary stepped down Tuesday following an extended dispute with President Donald Trump over flavored vape nicotine products, making him the fourth high-profile Trump administration departure this year, NBC News reported. The conflict centered on Trump's frustration with Dr. Makary's pace in approving flavored vapes for retail sale, as reported by The Wall Street Journal. The Trump administration sought to expand the availability of flavored vapes earlier this year, but Dr. Makary's office issued a memo blocking the authorization of several flavors. The disagreement put Dr. Makary "on thin ice" with the President, according to reports. An anonymous senior administration official told Politico the decision to remove Dr. Makary had been months in the making. His tenure was marked by mass layoffs, significant turnover among senior leadership, and policy disputes with lawmakers, drugmakers, and Trump, said the U.S. official. They characterized Dr. Makary's time as the FDA's commissioner as contentious, with persistent conflicts over regulatory decisions and agency direction.Watch the video below. Your browser does not support the video tag.