US President Joe Biden vowed to ensure a "peaceful and orderly transition" to his Republican predecessor and now successor, Donald Trump.
"We accept the choice the country made," the Democrat said, repeating that he believes "you can't love your country only when you win".
Biden also saluted Vice-President Kamala Harris as "a partner and a public servant" who ran an "inspiring" campaign after he dropped out.
His first public remarks after Tuesday's election, in the White House's Rose Garden, came as Democrats in Washington began seeking someone to blame for Harris's large loss to Trump.
Some Democrats have blamed Biden for Harris's election loss, suggesting that he should have dropped out of the race sooner or that the 81-year-old should never have run for a second term at all.
The incumbent sought to balance a conciliatory tone with a message of reassurance, after a bleak campaign season where Harris frequently said that a Trump victory would threaten democracy and Trump often described the US as a "nation in decline" and a "failed nation".
