The United States Republican presidential nominee Donald Trump has launched a rare attack on the first lady Michelle Obama, saying "all she wants to do is campaign" for his rival.

He also accused the first lady of attacking Hillary Clinton in 2007 by invoking a line she had said about fitness to run the White House.

Meanwhile, Mrs Clinton accused Mr Trump of threatening democracy if he did not accept the election result.

She said to a  crowd in Cleveland, Ohio, "We know the difference between leadership and dictatorship, and the peaceful transition of power is one of the things that sets us apart."

"Donald Trump refused to say that he'd respect the results of this election. By doing that, he's threatening our democracy."

Donald Trump said to his  supporters at a rally in North Carolina, "I see how much (Michelle Obama) likes Hillary."

"But wasn't she the one that originally started the statement, 'If you can't take care of your home,' right? 'You can't take care of the White House or the country?' Where's that? I don't hear that. I don't hear that."

Mrs Obama said that, "If you can't run your own house, you certainly can't run the White House".

"So, we've adjusted our schedules to make sure that our girls are first, so while he's traveling around, I do day trips," Mrs Obama continued in her 2007 speech.

"That means I get up in the morning, I get the girls ready, I get them off, I go and do trips, I'm home before bedtime."

Also Read: India, US would be 'best friends' if elected: Donald Trump

Nandini