"Did Crooked Hillary help disgusting (check out sex tape and past) Alicia M become a United States citizen so she could use her in the debate?" he added.
Machado, in her statement, says she will not back away from her remarks about Trump. He said she "duped and used" Clinton.
"When I was a young woman, the now candidate, humiliated me, he insulted me, he publicly disrespected me, like he accustomed to do in private in the most cruel of ways". Really, why does he do things like that?
Sarah Huckabee Sanders, a Trump adviser, complained on CNN that the media kept asking about the matter, even when host Carol Costello pointed out that Trump was the one helping to keep it in the news. At the same time, the tweets largely drowned out Clinton's policy speech, another example of the challenge she faces as she seeks to give voters a more uplifting message and a reason to vote for her, not just against Trump.
The controversy started when Clinton brought up Trump's comments and treatment of Machado at Monday's presidential debate. Trump returned with a new tweet invoking Clinton's famous ad from her 2008 campaign portraying her as the best candidate to pick up an urgent call at the White House at 3 a.m.
Trump, however, seems to be following a pattern of personal and sexually explicit attacks against women who have slighted him.
But Republicans might also worry that Clinton's ability to get under Trump's skin so easily has provided a blueprint that world leaders like Russia's Vladimir Putin could use to rile him as president.
The Clinton campaign denies playing any part in Machado's citizenship application, but seized on the apparently false rumours of a sex tape as evidence of an attempt to smear her in revenge for speaking out. He also promised to hit Clinton harder in their next debate, on October 9, suggesting he might attack Clinton on the infidelities of her husband, former President Bill Clinton.
Trump surrogates have also repeatedly brought up an attempted murder investigation involving Machado, although she was never charged. "Everybody has a past", she said.
In a series of tweets between 2:14 and 2:19 a.m., the Republican presidential candidate suggested that Clinton helped the Venezuelan-born 1996 Miss Universe become a US citizen "so she could use her in the debate". There are 38 days until the election.
Clinton's campaign chairman, John Podesta, mocked Trump on social media Friday morning. He then appeared to suggest, without citing any evidence, that Mrs. Clinton helped Ms. Machado obtain US citizenship so that her story could be better used in the debate.
Former President Bill Clinton and Chelsea Clinton, daughter of Hillary Clinton listen during the presidential debate between Republican presidential nominee Donald Trump and Democratic presidential nominee Hillary Clinton at Hofstra University in Hempstead, N.Y., Monday, Sept. 26, 2016. Clinton began. "Alicia deserves praise for courageously standing up to Trump's attacks".
"For those few people knocking me for tweeting at three o'clock in the morning, at least you know I will be there, awake, to answer the call!"
The Clinton campaign appeared to welcome the battle, and Clinton herself is expected to address Trump's tweets later today.