Celebrations for America’s 250th independence anniversary kicked into full gear, but storms threatened Donald Trump’s speech and forced an evacuation.

With temperatures forecast to reach up to 42 degrees, the US president told an audience he planned to make a long speech, “just to show that I can do anything”.

It’s an historic weekend in America, one that's been years in the planning, when the nation will mark the 250th anniversary of the declaration of independence.