4 months into his presidency, Mary Trump told her uncle Donald Trump not to let critics 'get you down.' Today, she would tell him to resign.

• Mary Trump, the niece of President Donald Trump, called on him to resign in her first public appearance since publishing a scathing tell-all about the president and the Trump family.
• Mary Trump spoke in an exclusive interview with ABC News on Tuesday following the publication of her new book, "Too Much and Never Enough: How My Family Created the World's Most Dangerous Man."
• Three years ago, she told her uncle not to let his critics "get you down," after seeing how "strained" he was by the "pressures" of the presidency.
• "I just remember thinking, 'He seems tired. This is not what he signed up for,' if he even knows what he signed up for," Mary Trump said, recalling the three times she visited her uncle in the Oval Office.
• "I thought his response was actually more enlightening than my statement. He said, 'they won't get me,'" she continued. "And so far, it looks like he's right."

Four months in Donald Trump's presidency, his niece Mary Trump told him not to let his critics "get you down."

Three years later, she only has one word of advice: "Resign."

Mary Trump spoke in an exclusive interview with ABC News on Tuesday, her first public appearance since publishing a scathing tell-all about the president and the Trump family, titled "Too Much and Never Enough: How My Family Created the World's Most Dangerous Man."

"Four months in, he already seemed very strained by the pressures," Mary Trump told ABC News' George Stephanopoulos. "He had never been in a situation before where he wasn't entirely protected from criticism or accountability or things like that."

"I just remember thinking, 'He seems tired. This is not what he signed up for,' if he even knows what he signed up for," she continued, recalling the three times she visited her uncle in the Oval Office.

Mary Trump went on to say that she was sincere in her advice to the president, but not in the sense of "I want you to keep doing what you're doing and get away with it," she said.

"I thought his response was actually more enlightening than my statement. He said, 'they won't get me,'" she said. "And so far, it looks like he's right."

However, after the last three years of Trump's presidency, Mary Trump said, today, she would instead call on her uncle to step down as president. She told ABC News that Trump was "perverted" by the Trump family's "issues," causing him to be "utterly incapable of leading this country."

"I saw first-hand what focusing on the wrong things, elevating the wrong people can do – the collateral damage that can be created by allowing somebody to live their lives without accountability," she told ABC News. "And it is striking to see that continuing now on a much grander scale."

Mary Trump's father, Fred Trump Jr., was Donald Trump's eldest brother. In her book, Mary Trump claimed that she and her brother were cut out the will of their grandfather, who died in 1999, due to their father's untimely death in 1981, as their grandfather's assets were primarily divided amongst his children.

Mary Trump wrote in her book that she and her brother filed a lawsuit to claim part of their grandfather's assets.

She later claimed in the book that the lawsuit prompted the rest of the Trump family "to cause us more pain and make us more desperate" by cutting off access to medical insurance that was previously provided to them through their grandfather's company.

Mary Trump faced pushback from her other uncle Robert Trump, Donald Trump's younger brother, who unsuccessfully tried twice to block her book from being published. However, a New York judge lifted the restraining order against the publisher and said the book was in "legitimate public interest" and lifted a gag order against Mary Trump allowing her to discuss the book.

Representatives from the White House did not immediately respond to Business Insider's request for comment. Previously, White House deputy press secretary Sarah Matthews said: "Mary Trump and her book's publisher may claim to be acting in the public interest, but this book is clearly in the author's own financial self-interest. President Trump has been in office for over three years working on behalf of the American people – why speak out now?"