Algae thwarts Trump's $14.2m attempt to turn reflecting pool 'American flag blue'

Donald Trump's $14.2m bid to turn the Lincoln Memorial reflecting pool from what the US president described as a "filthy" and "dirty" site into a "beautiful" monument has encountered a hitch.

The water is green again.

Days after the renovation was finished, algae has frustrated Trump's attempt to transform the shade of the pool to "American flag blue" in time for the country's 250th birthday.