SQL0552N user does not have the right privileges

hi! I'm getting this exception when trying to execute some commands in DB2 9.7 installed on linux system. SQL0552N "INST1" does not have the privilege to perform operation "CREATE TABLESPACE". SQLSTATE=42502.

Apparently, this user hasn't the right privileges to execute this operation. How can I give this user SYSCTRL or SYSADM authority, even if a database does not exist before running the command?

Please suggest!

Thank you in advance!