Donald Trump has described the arrest of five men near RAF Fairford as "fantastic", saying authorities believe they were part of a suspected terror plot targeting the US-used RAF air base. Trump praised the joint operation by US and British officials and said the suspects had been under investigation for some time and were looking to do "big damage". "The arrest in the UK was fantastic working with Britain. It was an amazing job," Trump told reporters as he arrived in Chicago. British police arrested the five men near the base on suspicion of terrorism and explosives offences. The arrests followed a tip-off about three suspicious vehicles heading towards the airfield early on Sunday. RAF Fairford has been used by the US for strikes on Iranian missile sites in the Strait of Hormuz. Strategic Analysis Australia director Michael Shoebridge told News24 host Jaimee Rogers the arrests and security operation appeared to point to a plot against the base. "This doesn't look like a coincidence; it does look like some plot to target this major US airbase," he said.