US marks its 250th birthday with fireworks, flyovers and extreme weather

"The American dream is back," US President Donald Trump told a cheering crowd at a delayed rally on the National Mall in Washington before the reputed largest fireworks display ever in the US lit up the night.

The sharply divided country has seen Trump criticised for making himself central to the milestone and politicising it by launching Freedom 250 celebrations, which are separate from congressionally established America 250 events.

The country's first black president, Barack Obama, reshared excerpts of a recent speech he made at his presidential museum's opening.