Israeli Prime Minister Benjamin Netanyahu said on Sunday that Israeli forces would remain in occupied regions of southern Lebanon "as long as necessary", while also vowing to prevent Iran from acquiring nuclear weapons.
"We will remain in the security zone in southern Lebanon for as long as necessary to protect the cherished residents of the north and all the citizens of Israel... Nothing will alter that commitment," Netanyahu said.
"And with regard to Iran: whatever political developments may unfold, I will not allow Iran to acquire nuclear weapons. As long as I serve as prime minister of Israel, that will not happen."
Israel's military chief said on Sunday that Hezbollah had suffered a severe blow fighting Israeli forces and was now in a "very difficult position", as he met with troops in southern Lebanon.
He spoke as the United States and Iran held talks in Switzerland after signing a preliminary agreement to end the broader Middle East war, with the conflict in Lebanon threatening to derail the deal.
"Hezbollah has suffered a severe and significant blow, and we are committed to remaining prepared to continue operating and prevent its rebuilding," Lieutenant General Eyal Zamir said, according to a military statement.
"Hezbollah is in a very difficult position," he added.
Hezbollah had pulled Lebanon into the Middle East war in early March when the Iran-backed Lebanese group fired rockets at Israel in retaliation for the killing of Iran's supreme leader in US-Israeli strikes.
Despite a new ceasefire announcement on Friday as part of the memorandum of understanding signed by Tehran and Washington, Israel and Hezbollah had continued to clash.
However, there were no reports of fresh strikes in Lebanon since Saturday evening.
Zamir vowed to defend the communities of northern Israel from Hezbollah rockets.
"This is the purpose guiding all our efforts... The ceasefire that has been declared is fragile, and we must maintain a high level of readiness for the renewal of combat operations," Zamir said.
- Qassem -
Hezbollah chief Naim Qassem on Sunday rejected any Israeli security zone in Lebanon.
Israeli troops "remaining on Lebanese land is impossible. There are no security zones for Israel... we have a national army which deploys, and it is responsible for preserving sovereignty, and it is who we cooperate with," Qassem said in a televised address.
"Israel is an aggressor and must leave. America bears full responsibility," he said, adding that "Israel will not remain in Lebanon, even if it increases its crimes, and we will defend ourselves."
Qassem's address came as Washington and Tehran held talks in Switzerland after this week signing a preliminary agreement to end the broader Middle East war, which includes a halt to the hostilities in Lebanon.
Ongoing Israeli strikes in recent days have threatened to derail the deal, but fighting in Lebanon has paused since Saturday evening, after Iran again closed the strategic Strait of Hormuz in response to Israel's attacks on Lebanon.
"Any ceasefire under the banner of a comprehensive cessation of hostilities -- we have already committed to this if it happens, but we will not accept any violation. We will confront any violation... we will deal with it as we see fit," Qassem said.
He urged Lebanese authorities to "take advantage of the path of the memorandum of understanding."
"Look at the great Iran, closing the Strait of Hormuz for the sake of Lebanon. This is a weapon in your hands," he said, addressing the Lebanese authorities, adding, "Take up this weapon and use it."
Under US pressure, Lebanon in April began direct talks with Israel in Washington aimed at ending the hostilities and separating the Israel-Hezbollah conflict.
Hezbollah has firmly rejected the direct talks, a fifth round of which is due to begin next week.
Earlier on Sunday, Defense Minister Israel Katz said Israeli forces had standing orders to act against any threat inside Lebanon and insisted they would remain in the so-called security zone established within occupied Lebanese territory.
"There has never been, and there is currently no restriction on Israeli soldiers in Lebanon from acting to eliminate threats... As Prime Minister Benjamin Netanyahu and I have made clear: Israel will not withdraw from the security zone in Lebanon," Israel Katz said in a statement, referring to an area extending roughly 10 kilometers (six miles) into Lebanese territory that Israel is occupying.
Israeli forces and Hezbollah fighters engaged in fierce clashes this week, with Lebanese officials reporting dozens of people killed and the Israeli military reporting five of its own soldiers dead.