Trump has promoted the idea of putting "gun-adept" teachers and staff in schools with concealed firearms to protect students after this month's shooting at a Florida high school killed 17 people.

But neither Trump nor the White House has said who would pay to train them. Trump has also called for giving bonuses to educators who volunteer to carry a firearm.

In his latest tweet he says: "Armed Educators (and trusted people who work within a school) love our students and will protect them. Very smart people. Must be firearms adept & have annual training. Should get yearly bonus. Shootings will not happen again - a big & very inexpensive deterrent. Up to States."

Australian Associated Press