Michelle Obama joined Hillary Clinton at a campaign rally to lend support to the presidential nominee in the closing stages of the race for the White House.
Obama boosted Clinton at a North Carolina rally as the candidate cheered her on, with Clinton hoping to succeed her husband Barack as US president.
She offered an impassioned tribute to Clinton as she praised her as the most prepared candidate for the presidency ever, adding: "Yes, more than Barack, more than Bill."
The women were unveiling a new 500 million US dollar policy plan aimed at reducing bullying. The Clinton campaign said her policy would provide funding to states that develop comprehensive anti-bullying efforts. It would be paid for through Clinton's proposed tax increases on the wealthy.
Obama also accused Trump's campaign of trying to depress voter turnout by deriding the election as "rigged". She told supporters that presidential races are decided on a "razor's edge".
"If Hillary doesn't win this election, that will be on us," she said.
With a steady lead in the race for weeks, Clinton's campaign is concerned that her advantage could prompt some of her backers to stay home on election fay or cast protest votes for a third-party candidate.
A new Associated Press- GfK poll released on Wednesday found Clinton on the cusp of a potentially commanding victory, fuelled by solid Democratic turnout in early voting, massive operational advantages and increasing enthusiasm among her supporters.
The survey shows her leading Trump nationally by a staggering 14 percentage points among likely voters, 51-37. That margin is the largest national lead for Mrs Clinton among recent surveys. But other polls generally have shown her ahead of Trump for the past several weeks.