Newly installed United States President Donald Trump's claim that over 1.5 million people turned up to witness his inauguration speech has been shot down by media outlets that, quoting experts, say the crowd size could have been less than half of that.

The reveal of photographs and video footage such as this time-lapse video drew flak from Trump's press secretary Sean Spicer who lambasted news reporters for trying to sow divisions in the country, adding that the new administration will hold them to account for what they publish.