How do I specify a password to 'psql' non-interactively?

I am trying to automate database creation process with a shell script and one thing I've hit a road block with passing a password to psql. Here is a bit of code from the shell script: psql -U $DB_USER -h localhost -c"$DB_RECREATE_SQL" How do I pass a password to psql in a non-interactive way?