Is it possible for an US resident to work for same employer in Canada?

[Semi-conc'nt 04]

I work for a large Company - based in the US, Canada, and the UK. There is a project - an opportunity that requires me to travel (probably, multiple times and for extended periods) to Calgary, Canada. My q's:

a) will I need a work permit (from the Immigration authority in Canada)?

b) will my residency status (with regard to naturalization) be affected?

Thanks.