Donald Trump fired off a series of tweets Friday morning accusing his Democratic opponent of securing citizenship for Alicia Machado, the former Miss Universe winner at the center of a campaign controversy, in order to use her as an attack line at the first presidential debate.

Trump has weathered criticism this week over 20-year-old comments he made about Machado's weight gain after her 1996 victory in the international beauty pageant Trump then owned. Hillary Clinton blindsided the billionaire on Monday by recounting his insults during the debate, telling Trump that Machado had recently become a U.S. citizen and planned to vote in November.

But in the wake of the debate, Trump has doubled down on his comments.

Machado embarked on a media blitz this week, slamming the Republican nominee in multiple interviews. The former Venezuelan beauty queen has said Trump called her "Miss Piggy" and "Miss Housekeeping" and claimed she developed an eating disorder after Trump disparaged her figure.

Trump has in turn accused Machado of acting out during her reign as Miss Universe and has argued the "massive amount of weight" she gained caused problems for the program. His allies have highlighted Machado's checkered past, such as her racy stint on a Spanish reality show and her alleged involvement in a 1998 murder.

When asked on Tuesday to address past reports that she drove the getaway car in a murder and subsequently threatened to kill the judge who indicted her boyfriend, Machado told CNN's Anderson Cooper that she was "not a saint girl" and did not deny the allegations.

The controversy over Trump's treatment of Machado has emerged as the dominant story line from his uneven performance at the first presidential debate. He has begun to consider publicly a strategy that would involve reviving decades-old attacks on the infidelities of Clinton's husband, to the dismay of many Republican strategists.

Amid a flurry of stories about his debate preparation and his handling of the Machado dust-up, Trump urged his supporters on Friday to disregard the chatter attributed to anonymous sources.

Railing against the media has been a feature of Trump's campaign since the very beginning. Even so, he has since refrained from blaming moderator Lester Holt for his unsatisfactory debate showing and even praised the NBC anchor for his performance in the spin room immediately following Monday night's event.