The scope of the authorization granted to the Israeli army for the expected attack on Beirut's southern suburbs remains unclear, Israeli newspaper Maariv reported on Monday.

Israel's defense minister said Monday there would be "no calm in Beirut" if Hezbollah attacks continued and vowed to establish a military-controlled zone in the area of south Lebanon's Litani River.

"The Dahieh in Beirut is no different from the communities in northern Israel -- if there is no calm in the north, there will be no calm in Beirut," Israel Katz said in a statement released by his office, referring to the Beirut southern suburb and Hezbollah stronghold where he had earlier Monday ordered strikes.

Israeli forces are making their deepest incursion inside Lebanon since they withdrew from the country over a quarter-century ago, despite a nominal U.S.-brokered ceasefire and the first direct talks between the countries in decades.

The Israeli advance presents a challenge in the emerging deal to extend the Iran war ceasefire as Tehran wants any agreement to end fighting in Lebanon, too. Qatar called it a "dangerous escalation." Germany's foreign minister said it was cause for serious concern, according to German press agency dpa. There was no comment by the United States.

Israeli troops have captured a strategic mountain topped with a Crusader-built castle in southern Lebanon in the deepest incursion into the country in more than a quarter-century, the military said Sunday, while U.S. Secretary of State spoke to Lebanese and Israeli leaders in an effort to keep negotiations going.

U.S. Secretary of State Marco Rubio spoke to Lebanese President Joseph Aoun and Israeli Prime Minister Benjamin Netanyahu to propose a fresh path to continue ongoing negotiations, according to a U.S. official who spoke on condition of anonymity to discuss private diplomatic conversations. Under the proposal, Hezbollah would halt all attacks on Israel and Israel would refrain from escalating military operations in the Lebanese capital of Beirut, according to the official.

The U.N. Security Council is set to hold an emergency meeting Monday on the fighting in Lebanon after Israel's military took over the medieval castle of Beaufort in Lebanese territory, diplomatic sources told AFP.

Israeli Prime Minister Benjamin Netanyahu has vowed to push deeper into Lebanon and called Sunday's operation a "dramatic shift" in the campaign against Hezbollah.

The latest U.S. push for a ceasefire in Lebanon has fizzled just as Israel is expanding its ground invasion and seeking a U.S. green light to conduct massive strikes on Hezbollah targets in Beirut's southern suburbs, sources told U.S. news portal Axios.

Israel's government ordered strikes on the southern suburbs of Beirut on Monday, a day after its ground forces reached their deepest point in Lebanon in 26 years and as Hezbollah fired rockets at northern Israel including the outskirts of coastal city of Haifa.

A joint statement by Israeli Prime Minister Benjamin Netanyahu and Defense Minister Israel Katz said that following what they called repeated violations of the ceasefire by Hezbollah and the "attacks against our cities and citizens," they have ordered the Israeli military to attack targets in Beirut's southern suburbs known in Arabic as Dahieh.

The Israeli army announced Monday that two of its soldiers had been killed in separate incidents in southern Lebanon, bringing to 27 the number of Israeli military deaths since early March.

President Joseph Aoun said Monday that Lebanon was facing "a vicious and reprehensible Israeli aggression", after Israel stepped up its offensive against Hezbollah with the capture of the medieval Beaufort Castle.

Aoun condemned the Israeli offensive in a post on X and pledged to "work to end the suffering of the Lebanese people, and people in the south in particular".

President Joseph Aoun is leading intensive efforts with the Americans in an attempt to reach a ceasefire or de-escalation and to halt the Israeli advance, the al-Modon news portal reported on Sunday