foreign country; another country
Neutral term for a country other than one's own. Used in news, formal contexts, and everyday speech.
Tourists from other countries are increasing.
It is important to learn about the cultures of other countries.
another province
Historical or literary use for a province other than one's own, especially in pre-modern Japan. Rare in modern contexts.
In the Edo period, a travel permit was needed to go to another province.
strange land; alien land
Literary or emotive nuance for a foreign or unfamiliar place. Often carries a sense of distance or otherness.
He felt lonely in a strange, foreign land.
He has lived in a foreign country for many years.
There are many international students who came from other countries.
Learning about the culture of other countries is fun.
He fled the war and crossed over into a foreign land.
異国 stresses the exotic, unfamiliar feel of a foreign land, whereas 他国 is a more neutral term for 'another country'.
他国 broadly means 'another/foreign country' with no implication of being outside a dispute, whereas 第三国 specifically means a country not party to a given matter.
Compound of 他 (other) and 国 (country). The reading たこく is a standard on'yomi combination.