He added, "What he did to our military made this country very unsafe for you and you and you". Trump didn't explain what he meant.
Michelle Obama writes in her biography that she was shocked the day Trump became president.
She continued, "I think it is the worst thing that we do as women: sit around and not talk about our bodies".
Mrs Obama will launch her book promotional tour in the USA on Tuesday not at a bookstore, but at Chicago's United Centre, where tens of thousands of people have purchased tickets - from just under $US30 ($A41) to thousands of dollars - to attend the event moderated by Oprah Winfrey.More news: Sabarimala review petitions to be heard in Supreme Court on Tuesday
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The memoir fulfills half of an agreement that publisher Penguin Random House reached with her and the former president after he left office under which the couple will each publish one book, reportedly for a sum worth more than $60 million. "But it was also risky, deliberately meant to stir up the wingnuts and kooks", Obama wrote. Though she initially wanted to keep their relationship in the friend zone, that went out the window when he kissed her for the first time.
Michelle also thought back to the first time she saw the infamous Access Hollywood tape, in which Trump is heard bragging about sexually assaulting women. She also reveals that she had both her daughters, Malia and Sasha, via in vitro fertilization.
"'What if someone with an unstable mind loaded a gun and drove to Washington?'" Stephanopoulos read on Good Morning America, quoting an excerpt from Becoming.
Ahead of the book's release on Tuesday, a Washington Post review has revealed that Obama makes damning criticism of the current U.S. president, saying that the "dangerous" conspiracy that claimed Barack Obama was not born in America could have endangered her family's safety.
She revisits the thrill of her romance with Barack, which began when she was his advisor at a Chicago law firm, describing it as a "toppling blast of lust, gratitude, fulfillment, wonder".
"I've never been a fan of politics, and my experience over the last 10 years has done little to change that", Michelle writes.