get country from list of cities/places

I have an unstructured list of cities/places and I need the list of countries in which these cities are located. The data comes from the origin written by users in their profiles in a rating website, therefore they are not structured. For example I have an entry like "Portland, Oregon" and I want the associated country, "United States" Some of these entries are just cities (e.g. "cheshire") or just countries (e.g. "Finland"). I need the country in which these places are located. I also have the geolocation of these cities (lat and log). My data are in the attachment.