Hezbollah chief Naim Qassem said negotiations with Israel under fire would amount to "surrender", as the Iran-backed group launched attacks and Israel said it was expanding a so-called "buffer zone" inside Lebanon.
Israel's Prime Minister Benjamin Netanyahu said the military had already "created a genuine security zone" and was now expanding it, pushing deeper into Lebanon.
"We are simply creating a larger buffer zone" that could prevent a ground invasion of Israel and missile attacks, Netanyahu said in a video shared by his office.
Hezbollah, meanwhile, issued dozens of statements claiming attacks on Israeli forces, and said it also launched missiles early on Thursday at military sites in central Israel, where air raid sirens sounded.
Channel 12 and other Israeli media reported that six rockets launched from Lebanon towards central areas were detected and intercepted, with emergency teams dispatched to inspect affected locations.
UN Secretary-General Antonio Guterres called on both sides to cease fire and warned Israel against replicating "the Gaza model" in southern Lebanon, raising fears of mass displacement.
Hezbollah said its fighters had launched more than 80 attacks on Wednesday, the largest daily number in the current war.
Lebanon was pulled into the Middle East war when Hezbollah began firing rockets into Israel on March 2 to avenge the killing of Iran's then-supreme leader Ali Khamenei.
Hezbollah chief Qassem on Wednesday said his group would have none of it: "When negotiations with the Israeli enemy are proposed under fire, this is an imposition of surrender."
Lebanon's state-run National News Agency reported Israeli strikes and artillery shelling in several locations in the south on Wednesday, where the health ministry said at least eight people were killed.
In southern Lebanon, Israel's military said ground troops "dismantled a weapons storage facility" and the air force killed "several terrorists".
Hezbollah said it clashed with Israeli forces using light and medium weapons as well as rocket-propelled projectiles on the road to the town of Qantara in southern Lebanon, and targeted an Israeli Merkava tank with a guided missile.
Warning sirens sounded across the greater Tel Aviv area following rockets launched from Lebanon, with Hezbollah saying it also targeted Israeli military sites in Tel Aviv with “precision missiles,” including the Kirya complex housing Israel’s Defence Ministry and the Dolphin barracks.
Israel has pounded Lebanon with air strikes and launched a ground offensive in southern Lebanon since a cross-border attack by Hezbollah on March 2.
Lebanese authorities say at least 1,094 people have been killed and 3,119 injured in Israeli attacks, with more than 1,000 killed in over three weeks of strikes, including 42 health workers, and upwards of one million people displaced.
The current escalation came amid a joint US-Israeli offensive on Iran which has killed more than 1,340 people since February 28, with Iran retaliating with drone and missile strikes targeting Israel and US-linked sites across the region.
