A friend wants to know if he can immediately visit Canada, within a few days, after he arrives for the first time as a US immigrant? He plans to just spend a few days in Canada to visit his relatives.
Assuming that he gets a temporary SSN or maybe a letter from the SSN office that he did apply for one and left for Canada, will he have any problems when he comes back to the US?
I'll advice him to at least apply for SSN and maybe check the local ins office before departing for Canada.