However the threat is not to the Queen or her party but to local business people.
The senior officer, who himself is travelling to Dublin to provide support during the three day visit, said there are concerns about the lack of cover locally.
The exact number of Gardai being deployed from Donegal cannot be confirmed for operational and security reasons.
But all leave for Gardai left behind has been cancelled while officers will carry out 12 hour rotational shifts to ensure a maximum of cover.
The Garda said the force in Donegal will be on high alert during the three day visit later this week while resources are stretched.
“I don’t think the safety issue will be with the Queen because there will be a huge ring of steel around Dublin and wherever she goes.
“The difficulty for the force locally will be the feeling by certain sections of the criminal fraternity that the door is open for them.
“It’s not an ideal situation but a lot of thought and planning has gone in as to how to best utilise our resources.
“But it is an issue. Donegal is a large county and because of the proximity to the border, the threat is always there,” he said.