U.S. President Donald Trump on Tuesday branded corporate chief executives "grandstanders" for quitting his advisory manufacturing council to protest his comments on last weekend's deadly white supremacists' rally in Charlottesville, Virginia. Hours later, Doug McMillon, chief executive of Walmart, the U.S.-based company that is the world's largest retailer, joined the other executives in rebuking Trump for his initial comments Saturday about the Charlottesville unrest. McMillon said Trump "missed a critical opportunity to help bring our country together by unequivocally rejecting the appalling actions of white supremacists." The Walmart chief added that Trump's Monday remarks explicitly condemning hate groups for the Charlottesville violence "were a step in the right direction and we need that clarity and consistency in the future." Kenneth Frazier, the chief executive of Merck Pharmaceuticals, CEO Kevin Plank of the Under Armour sporting goods company, and Brian Krzanich, who heads the technology giant Intel, all quit Trump's American Manufacturing Council on Monday. They were joined Tuesday by a fourth corporate leader, Scott Paul of the Alliance for American Manufacturing. Trump belittled the departures with a pointed retort on his Twitter account. "For every CEO that drops out of the Manufacturing Council, I have many to take their place. Grandstanders should not have gone on. JOBS!" he said. In a variety of comments, the corporate chieftains who quit Trump's manufacturing panel voiced their objections to Trump's first remarks about the Charlottesville protest, when he condemned the violence between white nationalists and counter-protesters, but did not single out neo-Nazis, the Ku Klux Klan and other hate groups by name as responsible for the street mayhem. Instead, Trump said the unrest was caused by "many sides." One woman was killed during the white nationalists' protest of Charlottesville's planned removal of a statue of Confederate General Robert E. Lee, leader of the Southern forces in the country's 19th century Civil War, a conflict fought largely over Southern states' demand to continue slave ownership. The woman, Heather Heyer, was killed when a white nationalist demonstrator drove his car at high speed into a crowd of counter-protesters. Prominent figures from across the U.S. political spectrum, Republicans and Democrats alike, assailed Trump's initial tepid response to the Charlottesville protest. But he returned Monday to Washington from his working vacation at his golf resort in New Jersey, and he explicitly denounced the hate groups who organized the Charlottesville rally, saying their "racism is evil." Merck chieftain Frazier was the first to quit the manufacturing council, saying Trump initially did not "clearly reject expressions of hatred, bigotry and group supremacy, which run counter to the American ideal that all people are created equal." Trump in July called Frazier a "business genius," but when he quit the manufacturing council, Trump, in less than a hour, said on Twitter that since he had left the panel he would now "have more time to LOWER RIPOFF DRUG PRICES!" Under Armour's Plank tweeted that he quit the council because he would rather unite people and promote diversity through the power of sports, not politics. Intel's Krzanich said he was resigning to highlight the "serious harm our divided political climate is causing to critical issues. I resigned because I want to make progress, while many in Washington seem more concerned with attacking anyone who disagrees with them. We should honor — not attack — those who have stood up for equality and other cherished American values." Paul, of the manufacturing lobbying group, said, “I'm resigning from the Manufacturing Jobs Initiative because it's the right thing for me to do.”