Hassan Nasrallah's comments were made as part of Lebanon's celebrations of the 6th anniversary of Israel's withdrawal from southern Lebanon after an 18-year occupation.
"What deters the enemy from launching an aggression is the resistance's continuous readiness to respond," the black-turbaned Nasrallah told scores of people who gathered in a Beirut hotel.
"Northern Israel today is within the range of the resistance's rockets. The ports, bases, factories and everything is within that range."
Nasrallah referred to statements he made years ago that his group has more than 12,000 rockets, reminding his listeners that "when I say we have more than 12,000 rockets I don't mean 13,000 rockets."
"I admit that the resistance has had for years - since 1992 - a respectable and strong rocket arsenal whether in quantity or quality," Nasrallah said.
Nasrallah's comments came amid increasing calls by some Lebanese politicians to disarm the terror group.