Donald Trump defended the National Rifle Association, Americans biggest gun lobby, saying it was led by "great people" who would "do the right thing" as he intensified his support for arming school teachers.

The US president said "attacks would end" if around a fifth of America's teachers were armed with concealed weapons and trained how to use them.

Wayne LaPierre, chief executive of the NRA, last night offered free firearms training to schools to stop the "evil that walks among us".

Mr Trump's enthusiasm for arming teachers was a response to America's worst ever high school shooting.

A total of 17 people died when Nikolas Cruz, 19, opened fire with a semi-automatic rifle at Marjory Stoneman Douglas High School in Florida last week.