US President Barack Obama and US Vice President Joe Biden speak after the election of Donald Trump in the US presidential election at the White House in Washington, US, November 9, 2016. [Photo/Agencies]

WASHINGTON - US President Barack Obama said Wednesday he had invited President-elect Donald Trump to the White House to "talk about making sure there is a successful transition."

Obama said he called Trump at around 3:30 am local time (8:30 GMT) to congratulate him on winning the election.

"We are all rooting for his success in uniting and leading the country," Obama said.

"The presidency and the vice-presidency is bigger than any of us," Obama said, and that his team was instructed to "work as hard as we can to make sure this is a successful transition."

"We are actually all on one team," Obama said as he tried to console those who were saddened by the outcome of the election.

"We are not Republicans first or Democrats First, We are Americans first," he said, adding "we all want the best for this country."

Obama also praised his party's nominee Hillary Clinton, whose candidacy and nomination was "historic" as it sends out a message that females can "achieve at the highest level of politics."

Clinton "has lived a extraordinary life of public service" as the First Lady, the senator of New York and the Secretary of State, Obama recounted.

Clinton has made a concession speech earlier in the day, congratulating Trump on his election and hoping for a peaceful transition of power.

US Republican Donald Trump defeated Clinton in the 2016 presidential election, pulling a major upset after a controversial and scandalous campaign cycle.