Separate grid rows by field value
Use Grouping by a Field

Grouping by Fields is a standard feature in Views. 


Create your Content Views with Page Display 
Add the Country Field (Probably a Taxonomy term reference, there are ways to import country lists BTW) 
Set Format to Grid and set Number of columns 
In Format Settings set Grouping field Nr.1 to your Country field  

Check in Preview that things look the way you want. 
Edit the Country field and set it to Exclude from display because you have it output above each result group, your probably don't want it in each grid cell too 
Edit the Country field Style settings if you want more control over how the "group headings" are output, but this works only in certain cases: D7 How to change the HTML wrapped around a grouping output (HTML h3 tag), D8 Allow to configure the h3 element for view style plugins, although you can use Custom text field for more control too.