US President Barack Obama has invited President-elect Donald Trump to meet with him to discuss the handover of power from his administration to Mr Trump's.
The White House said Mr Obama called the Republican in the early hours of the morning to congratulate him on his victory in the presidential campaign, which marked a forceful rebuke by voters to Mr Obama's eight years in office.
The two leaders planned to meet on Thursday at the White House, where Mr Obama will update Mr Trump about ongoing planning for the transition.
Mr Obama will offer his first reaction to the election later today in a televised statement that the White House said would focus on "what steps we can take as a country to come together after this hard-fought election season".
"Ensuring a smooth transition of power is one of the top priorities the president identified at the beginning of the year and a meeting with the president-elect is the next step," White House press secretary Josh Earnest said.
For Mr Obama, the act of holding the meeting is a humbling blow to his legacy and to his hopes for leaving a lasting imprint on the nation's policies.
Mr Trump has vowed to rip up much of what Mr Obama accomplished, including his signature health care law, the Iran nuclear deal and a painstakingly negotiated trade deal with Asia.
Mr Obama also called Hillary Clinton after it became clear she had lost the race. The White House said Mr Obama had "expressed admiration for the strong campaign she waged throughout the country".
It was unclear how substantive Mr Obama's call was with Mr Trump, or how long it lasted, although the White House noted that Mr Obama placed the call from his residence in the White House, rather than from the West Wing.
Mr Trump's campaign manager, Kellyanne Conway, described it as a "warm conversation" and a "gracious exchange". She said Mr Trump had missed the president's original call as Mr Trump was speaking to supporters in New York, then called him back after leaving the stage.
Like Mrs Clinton and other Democrats, Mr Obama did not appear to see Mr Trump's victory coming.
As he campaigned vigorously for Mrs Clinton in the race's final days, Mr Obama said he was confident that if Americans showed up to vote, they would choose against electing the billionaire former reality TV star with no formal government experience.
He had also warned supporters in apocalyptic terms that "the fate of the republic" rested on Mrs Clinton defeating Mr Trump on election day.