Cahill told the Evening Standard that it is important for the rest of the squad to help Kane focus on firing England deep into the tournament.
"It's important the experienced members of the squad help him so he can concentrate on finding the net," the defender said. "The message has been clear from the manager that he wants a number of leaders - that is why he passed the armband on to a few players before the tournament.
"He wanted that group of leaders to help and share the workload. I'm there to help. I'm not there to preach to anyone, but I have experience of playing in big games. If people want to speak to me and likewise me with other people, the group is very tight in that way and everyone is approachable for any type of advice in good and bad moments.
"Everyone prepares in their own way. Some people want that, some people don't. We'll be ready fitness wise for sure, it's just about being ready in the mind in a positive way."
Cahill is the most-capped player in Southgate's squad, with 59 appearances to his name.