The sheriff of a Florida county that endured America's latest school massacre has ordered his deputies to carry rifles on school campuses.

“Qualified and trained” officers “will be carrying rifles on school grounds from this point forwards”, Broward County Sheriff Scott Israel said at a news conference.

The guns will be stored in police vehicles when officers are not carrying them, Mr Israel said. He said he had the support of the school district's superintendent, pledging that “it will be done safely”.

“We need to be able to defeat any threat that comes onto campus,” he said.

A gunman killed 17 students and teachers last week after opening fire at Marjory Stoneman Douglas High School.

While some of the students who survived the massacre have emerged as vocal advocates for gun control, travelling to the statehouse in Tallahassee to urge a ban on assault weapons, others have advocated arming school personnel to defend against future shooters.

Florida shooting – in pictures Show all 10 1 /10 Florida shooting – in pictures Florida shooting – in pictures Police arrest a suspect in connection with the shooting at the Marjory Stoneman Douglas High School in Parkland, Florida Reuters Florida shooting – in pictures Parents wait for news after reports of a shooting at Marjory Stoneman Douglas High School in Parkland, Florida AP Florida shooting – in pictures Anxious family members wait for news of students AP Photo/Wilfredo Lee Florida shooting – in pictures Students being evacuated from the school AP Florida shooting – in pictures Students being evacuated from the school Getty Florida shooting – in pictures People gather waiting for word from students AP Florida shooting – in pictures Parents waiting for news on their children AP Florida shooting – in pictures People gather at a hotel where students were taken after the shooting Getty Florida shooting – in pictures Florida Governor Rick Scott speaks to the media as he visits Marjory Stoneman Douglas High School following the shooting AFP/Getty Florida shooting – in pictures Dr. Igor Nichiporenko, Medical Director Trauma, left, and Dr. Evan Boyer, Medical Director, Emergency Services, speak about treating victims and the suspect at a press conference outside Broward Health North hospital AP

Donald Trump embraced the concept during a White House meeting with survivors of shootings and family members of victims.

Father of Florida victim: 'We, as a country, failed our children'