Greene said on Saturday that Trump's online criticism had unleashed a surge of threats directed at her. On Sunday morning, she told CNN that Trump calling her a traitor was the "most hurtful" part of his remarks.
Trump repeated the insult hours later.Â
"Marjorie 'Traitor' Greene," he said.
"I don't think her life is in danger ... I don't think anybody cares about her," the president told reporters before boarding Air Force One on Sunday night to return to Washington, DC from his Mar-a-Lago social club in Florida.
Greene, a US House of Representatives member from Georgia who was a Trump loyalist, has recently taken positions at odds with the president.
She said on Saturday she has been contacted by private security firms warning about her safety and that harsh attacks against her have previously resulted in death threats.
She attributed her split with the president to her support for releasing records related to the late financier and sex offender Jeffrey Epstein.
Trump has dismissed the furore over the Epstein case as a "hoax" pushed by Democrats, but Greene on Wednesday was one of four House Republicans who joined Democrats in signing a petition to force a vote on releasing the full Justice Department files related to Epstein.
The dramatic rupture between two longtime allies suggests a deeper fracture within Trump's Republican base and raises questions about the stability of his support on the far right of the ideological spectrum.
Trump broke with Greene on Friday night in a withering social media post in which he referred to Greene as "Wacky" and a "ranting lunatic".
He continued with more social media posts over the weekend, calling her a "Lightweight Congresswoman," "Traitor" and a "disgrace" to the Republican Party.
The president also wrote that conservative voters in Greene's district might consider a primary challenger and that he would support the right candidate against her in next year's congressional election.
Despite his attacks on Greene, Trump on Sunday night wrote on social media that "House Republicans should vote to release the Epstein files, because we have nothing to hide ..."
Over the weekend, Trump had persistently pushed back against reporters' questions about releasing the Epstein files.
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