To what extent is it mandatory to have an invitation to a visit to apply to a country like Canada or Russia? I wanted to visit one or the other of the two, but I did not understand how the processes unfolded and I also hear that it is mandatory to receive a letter of approval. invitation before the visit. In case I have no one on site and all that I will have for lodging is the reservation of a hotel (hotel reservation), can this work at this stage? Not a frequent traveler in Eastern Europe / EurAsia and the Americas, so I just wanted to be sure of things in advance.
In addition, I am a Nigerian citizen and I need clear and concise answers.