To secure your system, you shouldn’t allow root to login remotely. Instead, if an admin needs to use the root account they should login using their own account and then su - or sudo to the root account as needed.

Edit the /etc/ssh/sshd_config file and change the following lines:

PermitRootLogin no PermitEmptyPasswords no

Some of these properties may be commented out in the file, so all you’d need to do is remove the # sign.