President Trump ushered in the 250th anniversary of American independence on Friday with soaring rhetoric about American exceptionalism before veering into a darkly political speech with warnings about a sinister threat of communism that evoked one of the country's ugliest chapters.

He urged Congress to pass ​legislation that would limit mail ballots and require proof of citizenship to register to vote, and said he had "wiped out" Iran's military.

US President Donald Trump's speech included some of his political agenda but also honoured war veterans and American history.