“The enemy knows well that we have prepared ourselves for the worst… and that no place… will be spared our rockets,” he said.
He added that Israel must expect “us on land, by sea and by air”.
“The enemy really fears that the resistance will penetrate Galilee” in northern Israel, he said, adding that this was possible “in the context of a war that could be imposed on Lebanon”.
Israel and Hezbollah, a powerful Lebanese movement allied with Hamas, have traded near-daily cross-border fire since the Palestinian militant group’s Oct 7 attack on Israel which triggered war in the Gaza Strip.
The exchanges between the foes, which last went to war in 2006, have escalated in recent weeks, and the Israeli military said on Tuesday that “operational plans for an offensive in Lebanon were approved and validated”.
Earlier, foreign minister Israel Katz had warned of Hezbollah’s destruction in a “total war”.
Call for urgent de-escalation
Mr Nasrallah’s statements came a day after US envoy Amos Hochstein – who in 2022 brokered a maritime border deal between Israel and Lebanon – called for “urgent” de-escalation, during a visit to Lebanon. He also met with senior officials in Israel on his regional tour.
“Everything the enemy says and that the mediators convey, including with threats of war on Lebanon… this doesn’t scare us,” Mr Nasrallah said.
On Tuesday, Hezbollah released a more than nine-minute video showing aerial footage purportedly taken by the movement over northern Israel, including what it said were sensitive military, defence and energy facilities and infrastructure in the city and port of Haifa.
Mr Nasrallah said the footage was taken by a drone that “flew for long hours” over the Haifa port. He also warned that his group had only used “a part of” its weapons since October.
“We have obtained new weapons,” Mr Nasrallah said. “We have developed some of our weapons… and we are keeping others for the days that will come.
“Years ago we talked about 100,000 fighters… today, we have greatly exceeded” that number. The resistance has more manpower than it needs… even in the worst circumstances.”
Fatalities in northern Israel
Hezbollah on Wednesday claimed several attacks on Israeli troops and positions in northern Israel, and announced the death of four of its fighters.
The cross-border violence has killed at least 478 people in Lebanon, most of them fighters but also including 93 civilians, according to an AFP tally.
Israeli authorities say at least 15 soldiers and 11 civilians have been killed in the country’s north.