US president Donald Trump uses a primetime address on Tuesday to tell Americans he needs billions of dollars from Congress for his long-promised border wall to keep out drugs, gangs and human traffickers. In an Oval Office address, he says there is a 'growing humanitarian and security crisis' at the US-Mexico border, though crossings have fallen in recent years. He claims the wall will pay for itself via a new trade deal with Mexico and asks: 'How much more American blood must we shed before Congress does its job?'