You learned that 我が means "our", so our country is simply our country.
Just like 我が itself, this expression is somewhat old-fashioned and stylized. It comes up a lot in political discourse and other formal contexts.
You learned this reading for 我 when you learned 我が. Just watch out for 国, which you might expect to rendaku here, but doesn't!
Most of the politicians in our country are men.
In our country, mandatory vaccination of the population is under consideration.
Currently, foreigners without resident status are not allowed to enter our country.