President Barack Obama has strongly backed White House hopeful Hillary Clinton at the Democratic National Convention, denouncing deep Republican pessimism which he warned was fanning resentment and hate during the 2016 election cycle.

Key points: Mr Obama praised Mrs Clinton as the "most qualified" presidential candidate ever

Mr Obama praised Mrs Clinton as the "most qualified" presidential candidate ever Called on the party faithful to "reject fear" in the upcoming election

Called on the party faithful to "reject fear" in the upcoming election Accused Republicans of fanning "anger and hate" ahead of the vote

"I am more optimistic about the future of America than ever before," Mr Obama told thousands of delegates at the convention, praising Mrs Clinton as uniquely qualified to succeed him.

He said at the Republican convention last week, "there were no serious solutions to pressing problems — just the fanning of resentment, and blame, and anger and hate".

The President praised Mrs Clinton for blasting through "glass ceilings" as the first woman presidential nominee from a major US political party, calling her the most qualified person ever to seek the White House.

"I can say with confidence there has never been a man or a woman — not me, not Bill [Clinton], nobody — more qualified than Hillary Clinton to serve as president of the United States of America," he said.

Earlier this week, the convention formally anointed Mrs Clinton as the Democratic nominee, and she will now go up against her Republican counterpart Donald Trump in November's election.

Mr Obama hugged Mrs Clinton on the convention stage after his address. ( AFP: Saul Loeb )

"Tonight, I ask you to do for Hillary Clinton what you did for me. I ask you to carry her the same way you carried me," Mr Obama said.

To the strains of Stevie Wonder's Signed, Sealed, Delivered, Mr Obama shared a warm embrace with his would-be successor, capping an all-star night that included appearances by Vice President Joe Biden, Mrs Clinton's running mate Tim Kaine and independent Michael Bloomberg, the former mayor of New York.

Sorry, this video has expired Joe Biden: "Trump has no clue about what makes America great"

"This year, in this election, I'm asking you to join me to reject cynicism, reject fear, to summon what's best in us, to elect Hillary Clinton as the next president of the United States," Mr Obama said as he concluded his remarks.

Mr Obama and Mrs Clinton were rivals in the hard-fought campaign for the 2008 Democratic nomination.

After winning that election to become America's first black president, he appointed her his secretary of state.

Members of the crowd hold up Barack Obama signs at the Democratic National Convention. ( AFP: Robyn Beck )

Trump 'not really a facts guy'

Mr Obama belittled Mr Trump as having no economic or foreign policy plans, and added he was "not really a facts guy either".

"Does anyone really believe that a guy who's spent his 70 years on this Earth showing no regard for working people is suddenly going to be your champion? Your voice?" he said.

"If so, you should vote for him. But if you're someone who's truly concerned about paying your bills, and seeing the economy grow, and creating more opportunity for everybody, then the choice isn't even close.

"Our strength, our greatness does not depend on Donald Trump. In fact, it doesn't depend on any one person, and that in the end may be the biggest difference in this election — the meaning of our democracy."

Sorry, this video has expired Obama says Donald Trump is not a "plans guy, or a facts guy either"

The President also turned to Republican icons of yesteryear as comparison to highlight how Mr Trump was unprepared for the most important job in the world.

"Ronald Reagan called America a shining city on a hill," Mr Obama recalled.

"Donald Trump calls it a divided crime scene that only he can fix.

"We're going to carry Hillary to victory this fall, because that's what the moment demands," he said to loud cheers and applause.

"The Democratic Party is in good hands."

AFP/Reuters