Eliza Collins

USA TODAY

President Obama has some advice to Hillary Clinton ahead of Monday’s debate against Donald Trump.

"Be yourself and explain what motivates you," President Obama said in an interview with ABC News that aired on Good Morning America Friday.

"I've gotten to know Hillary and seen her work and seen her in tough times and in good times. She is in this for the right reasons. She is motivated by a deep desire to make things better for people,” he continued.

Despite a bitter primary between the two in the 2008 election, Clinton went on to serve under Obama as his secretary of State.

"I think there is a reason we haven't had a woman president before, and so she is having to break down some barriers," he said. "There is a level of mistrust and a caricature of her that doesn't jibe with who I know, this person that cares deeply about kids, and wants to make sure they get a good education and wants to make working families have support and wants everyone to succeed and wants to keep America safe."

Sept. 26 will be the first of three general election debate between Clinton and Trump at Hofstra University in New York.

Hillary Clinton prepares for ‘reality show’ debates

Trump lobbies moderators ahead of debate