“I am ashamed of the way my country has acted with respect of those children. I am disgusted, I am horrified, I am embarrassed, I’m ashamed,” Mr Comey said in a public interview in Dublin on Friday.

“My wife and I were joking, not really joking; we wanted to tell the people on the customs line coming here that we were Canadian. And we were joking but it’s funny because it reveals a truth: I’m ashamed.”

However, he said many Americans felt the same way and there was an historic pattern of reaction to social issues, including the civil rights movement.