When I was testing my new FreeBSD 10 RC, I was not able to connect from remote machine using root user.

Using username "root".
Access denied
Using keyboard-interactive authentication.
Password for root@Freebsd10:Access denied

vi /etc/ssh/sshd_config

Find this line:

#PermitRootLogin no

and change it to:

PermitRootLogin yes

Now Restart sshd

root@Freebsd10:~ # /etc/rc.d/sshd restartPerforming sanity check on sshd configuration.Stopping sshd.Waiting for PIDS: 1698.Performing sanity check on sshd configuration.Starting sshd.

Now you are Ready :

Using username "root".Last login: Fri Dec 13 15:15:40 2013FreeBSD 10.0-RC1 (GENERIC) #0 r259068: Sat Dec 7 21:12:15 UTC 2013Welcome to FreeBSD!FreeBSD Welcome to Unixmen Test Machineroot@Freebsd10:~ #