noun
various foreign countries; several foreign countries
Refers to multiple foreign nations collectively, often used in news or formal contexts.
諸外国の首脳が会議に出席した。
Leaders from various foreign countries attended the conference.
この政策は諸外国から批判されている。
This policy has been criticized by several foreign countries.
諸国 means various countries in general, not necessarily foreign; 諸外国 explicitly means foreign countries.
Compound of 諸 (sho, 'various') + 外国 (gaikoku, 'foreign country').