US President Donald Trump struggled to pronounce the word anonymous during his condemnation of a New York Times column that has thrown the White House into turmoil.
Speaking during a campaign rally in Montana, President Trump launched a tirade against a New York Times op-ed written by an unnamed Trump administration senior official.
The opinion piece described the president as "amoral" and making "reckless decisions".
The New York Times said it will not be revealing the identity of the author because he or she is “a senior official in the Trump administration whose identity is known to us and whose job would be jeopardised by its disclosure.”
Mr Trump said he won't be settling for that response.
"The latest act of resistance (to my administration) is the op-ed in the failing New York Times," he said.
He condemned the author as a "gutless coward" for hiding their identity but stumbled over the word anonymous twice.
President Trump said he believed the author was a female and suggested reporters at the New York Times should investigate the individual.
The rally in Montana was held as part of campaigning ahead of the November mid-term elections.
President Trump said Supreme Court candidate Judge Brett Kavanaugh has his support, as does Republican challenger Matt Rosendale.
Mr Rosendale is challenging Democratic Senator Jon Tester.
