I have a green card which I obtained a number of years ago. About 2 years ago, it expired, and I never renewed it. I do not plan to renew it ever.
I currently live in Canada as a permanent resident, work in Canada (Canadian income only, and file Canadian taxes), and I have never worked or lived in the US. A tax accountant has asked me whether I have a green card since I will be leaving Canada to work in another country, and I stated the above. The accountant told me that I may be non-compliant since I've never filed taxes in the US.
Is this true? Do I need to file taxes at any levels in the US?

