US President Barack Obama pledged to work for a smooth transition of power with President-elect Donald Trump.
In brief remarks to reporters in the White House Rose Garden, Mr Obama urged fellow Democrats to put aside their disappointment and tried to strike a positive tone after a devastating electoral defeat.
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"It is no secret that the president-elect and I have some pretty significant differences," Mr Obama said.
"We are now all rooting for his success in uniting and leading this country. The peaceful transition of power is one of the hallmarks of our democracy."
Mr Trump had long questioned whether Mr Obama had been born in the United States and his eligibility for office.
Mr Obama and wife Michelle had campaigned hard for Democrat presidential candidate Hillary Clinton, acknowledging that the president's legacy on healthcare, climate change and financial reforms were on the line.
Though Mr Trump has promised to undo Mr Obama's top domestic and foreign policy initiatives, the president kept his remarks focused on ensuring a successful transition, noting that his Republican predecessor, former President George W. Bush, had done the same for him eight years ago.
Mr Obama said defeated Democratic candidate Hillary Clinton had been an outstanding secretary of state, senator and first lady.
"I could not be prouder of her. She has lived an extraordinary life of public service.
"I'm proud of her. A lot of Americans look up to her.
"Her candidacy and nomination was historic and sends a message to our daughters ... that they can achieve at the highest levels of politics.
"Everybody is sad when their side loses their election. But the day after, we have to remember that we're actually all on the same team.... We are Americans first, we're patriots first.
"We all want what's best for our country."
Mr Trump has said he would would appoint a special prosecutor to investigate Mrs Clinton and that she would go to prison over her private email arrangements while secretary of state.
A White House spokesman said Mr Obama hopes the US tradition of people in power not using the criminal justice system against their opponents would continue.
"We've got a long tradition in this country of ... people in power not using the criminal justice system to exact political revenge. ... The president is hopeful that it will continue," White House spokesman Josh Earnest told a news briefing.