You could use a decision diamond in a campaign to determine which country the contact is from and then assign the contact to the specific lead using the ‘Assign an Owner’ functionality.
The following response to a similar question shows how to assign an owner based on which State someone is from: Alert notification to assigned owner of imported lead - #2 by Timothy_Smith
You would just need to replace ‘State’ with ‘Country’, and adjust the campaign to meet your needs.