The row over Donald Trump’s alleged remarks denigrating American soldiers has now seen the US president target one of his core areas of support as he called for a Fox News journalist who reported details of the scandal to be fired. The Atlantic magazine published a story that described how Trump said he cancelled a visit to pay respects at an American military cemetery outside Paris in 2018 because he thought the dead soldiers were “losers” and “suckers”. Other outlets confirmed the news and detailed more incidents of Trump’s insulting attitude to American soldiers. Among those was the Fox News national security correspondent, Jennifer Griffin, who confirmed in a Twitter thread that Trump called soldiers “suckers”, had questioned why anyone would want to become a soldier and had not wanted to honor war dead at the Aisne-Marne cemetery in France. Amid furious denials of the story from the White House and Trump allies, Griffin’s reporting probably touched a nerve as it came from the usually reliably pro-Trump Fox News, whose conservative leanings and pro-Trump opinion show hosts are reliable cheerleaders for the president. In a tweet Trump said: “Jennifer Griffin should be fired for this kind of reporting. Never even called us for comment. Fox News is gone!” The White House has moved to deny the report unusually forcefully perhaps fearful of the scandal’s impact on military-supporting conservatives. Trump himself dismissed it as a politically motivated “hoax”. “There is nobody feels more strongly about our soldiers, our wounded warriors, our soldiers that died in war than I do,” he told reporters at the White House on Friday. “It’s a hoax,” he said on Friday night. The first lady, Melania Trump, also weighed in, in a rare political intervention tweeting that the Atlantic story “was not true”. But Trump’s former chief of staff John Kelly, a retired marine corps general, has remained notably silent about the president’s comments. The Atlantic reported that Trump accompanied Kelly, who was the homeland security secretary at the time, to Arlington National Cemetery on Memorial Day 2017. While standing at the grave of Kelly’s son, who was killed in Afghanistan in 2010, Trump reportedly turned to Kelly and said: “I don’t get it. What’s in it for them?” Multiple reports say that close friends and associates of Kelly have encouraged him to speak out, but Kelly has refused on-the-record interviews about the comments. Anthony C Zinni, a retired marine corps general and close friend of Kelly, told the New York Times that Kelly is likely trying to “avoid taking a position that might be perceived as political”. “I also think he takes to heart the commitment to confidentiality in matters related to their interaction with the president,” he said. Meanwhile, Trump, who has speculated that Kelly might have been a source for the Atlantic story, said on Friday that Kelly “was totally exhausted” and “wasn’t even able to function in the last number of months” during his time in the Oval Office. Other senior military officials, including Jim Mattis, also a retired marine corps general and Trump’s former secretary of defense, have been silent about the comment. Trump’s Democratic challenger, the former vice-president Joe Biden, pounced on the news amid broad-ranging condemnation of Trump’s reported remark. Biden called the alleged comments “disgusting” and said Trump was “not fit to be commander-in-chief”. “When my son volunteered and joined the United States military – and went to Iraq for a year, won the Bronze Star and other commendations, he was not a sucker,” Biden said in emotional remarks in Wilmington, Delaware. His son Beau, who died of brain cancer in 2015, deployed to Iraq in 2008.