nations; states; various countries
Refers to multiple countries collectively, often in diplomatic or historical contexts. Common in phrases like 列国会議 (international conference) or 列国間の協定 (agreement among nations).
Representatives of various nations gathered in Geneva.
The nations signed the treaty.
Tensions among the nations are rising.
A new agreement was concluded among the nations.
Prime ministers of various nations attended the emergency meeting.
各国 emphasizes 'each individual country' when comparing or listing them separately, whereas 列国 treats the nations as a collective diplomatic group.
万国 means 'all nations of the world' and appears in set phrases like 万国博覧会, while 列国 refers more narrowly to the nations involved in a particular diplomatic context.
列島 (archipelago, a chain of islands) shares the kanji 列 with 列国 (various nations) but refers to a geographic landform, not a group of countries.
A Sino-Japanese compound corresponding to Chinese 列国, meaning the various states or countries considered collectively.