Change language of system and error messages in PostgreSQL

Question

Is it possible to change the language of system messages from PostgreSQL?

In MSSQL for instance this is possible with the SQL statement SET LANGUAGE.

Answer 1

For me neither Milen A. Radev's nor user1's answer worked - editing PostgreSQL\11\data\postgresql.conf had absolutely no effect. Even after setting lc_messages = 'random value' PostgreSQL would still start.

What helped was to delete PostgreSQL\11\share\locale\*\LC_MESSAGES, after that I finally got English messages.