Suspect charged after latest attempted assassination of Trump

US federal prosecutors on Sept 16 criminally charged a gunman suspected of attempting to assassinate Donald Trump, a day after he was spotted with a rifle hiding in the bushes at Trump's Florida golf course.

Ryan Wesley Routh, 58, was charged with possession of a firearm by a felon and possession of a firearm with an "obliterated" serial number, CNN reported, in what is likely a preliminary move to allow the authorities to keep him in custody while additional charges are brought.

Agents opened fire on a gunman who was spotted with an assaultstyle rifle hiding in bushes at one of the former US president's Florida golf courses, a few hundred metres from where Trump was playing.

The suspect fled by car, leaving behind two backpacks and his weapon, and was later arrested.

Routh appeared in a federal courtroom in West Palm Beach, Florida, a CNN reporter said on social media.

Routh was wearing dark prison scrubs and his hands and feet were shackled, the reporter said.

Trump, the Republican presidential candidate, was safe and unharmed, but the incident raised fresh questions about how an armed suspect was able to get so close to him, just two months after another gunman fired at Trump during a July 13 rally in Butler, Pennsylvania, grazing his ear with a bullet.

The Secret Service, which protects presidential candidates, "needs more help", including possibly more personnel, US President Joe Biden told reporters on Sept 16.