Donald Trump has pledged $5,000 (£3,700) to every American if the Republicans win the midterm elections in November.

The US president offered no details on how the plan would work or where the money would come from.

Democrats labelled it an "empty promise" and others have questioned whether such a pledge is even legal

BBC North America editor Sarah Smith looks into whether Trump's promise – which would cost the US government some $1.3 trillion – stands up.