Peter Edwards was seen getting off a bus in Barclay Street, Stonehaven at 3.20pm.
Mr Edwards was reported missing by family members after leaving his home in Scone early on Tuesday morning.
He took a number 7 bus into central Perth, getting off at Glasgow Road, near the Lovat Hotel, at 7.43am.
Investigators have disclosed that Mr Edwards arrived in Aberdeen at around noon, before boarding the 2pm bus to Stonehaven.
Mr Edwards was spotted on CCTV as he left the bus at 3.20.pm. Police Scotland are studying all available footage closely in a bid to track the 65-year-old down.
Mr Edwards, who originally hails from New York, has been a pastor at the Perth Christian Fellowship church for 30 years.
Peter’s friends and family are concerned that he may have fallen ill after wandering off.
Mr Edwards is described as 5ft 9in, balding with a grey beard and sideburns. He can normally be seen wearing gold rimmed spectacles.
When last seen, he was wearing a long sleeved grey shirt, black tank top jumper, tie, grey trousers and black leather shoes. He speaks with a distinctive American accent.
A Police Scotland spokeswoman said: “There is concern for Peter’s welfare and officers would like to hear from anyone who has seen him or has any information about his whereabouts.”
Police have ruled out a possible sighting at Christies Bar in Perth on Tuesday evening.