Aboard Air Force One (AFP) - US President Donald Trump on Tuesday (Oct 3) said he did not know whether Stephen Paddock, the gunman behind the deadliest gun attack in modern US history, was linked to the Islamic State in Iraq and Syria (ISIS) group.

ISIS has twice said that the Las Vegas shooter, a 64-year-old retired accountant, was one of its "soldiers" via its propaganda news agency Amaq, without providing evidence.

Asked by a reporter aboard Air Force One whether be believed the link to be true, Trump said: "I have no idea."