The meeting between the incoming and outgoing presidents of the United States was "excellent", said President Barack Obama.

But faced with a room full of journalists in the Oval Office after their 90-minute closed-door discussion, the two men seemed sombre and subdued, demonstrating little of the lighthearted moments of past first meetings between the president and president-elect.

There was no customary photo opportunity of the first couples at the south entrance of the White House.

The media was also not allowed to observe the Obamas greeting the Trumps as they arrived in their motorcade.

The White House insisted the meeting was "a little less awkward than some might have expected".