Messages from PostgreSQL

Good afternoon all !
I am developping a C++ application using libpq++
In that application, I create some tables in a dynamic way at the
execution.
So PostgreSQL give me at every time this message :

NOTICE: CREATE TABLE/PRIMARY KEY will create implicit index '_XXX_pkey'
for table '_XXX'

It is not very bad but a little boring because I perform many times
that operation.
How to avoid printing this message? Is there some option to do it?

Thank you all,
Renaud THONNART