Lebanon said an Israeli strike hit near a hospital in the southern city of Tyre on Monday as the health ministry shared footage showing heavy damage to the facility.

Iran's Revolutionary Guards threatened to open "new fronts" and keep the Strait of Hormuz closed over Israel's offensive in Lebanon, state media reported on Monday.

The United Nations on Monday expressed its alarm and called for all sides to respect the ceasefire as Israel expanded its offensive into Lebanon, while negotiations to end the U.S.-Iran war appeared in peril.

Israeli Prime Minister Benjamin Netanyahu said on Monday he told U.S. President Donald Trump that Israel would strike Beirut if Hezbollah doesn't stop attacking Israel.

Lebanon's U.S. embassy said on Monday that Hezbollah had accepted a U.S. proposal for a "mutual cessation of attacks", after Israel threatened more strikes on south Beirut on the eve of a fourth round of Israel-Lebanon negotiations.

Israel said Monday it would once again target Beirut's southern suburbs, a Hezbollah stronghold mostly spared heavy attacks since April, as it stages its deepest incursion into Lebanon in two decades.

Iran's Tasnim news agency said Tehran was suspending all exchanges with mediators in peace talks with the United States on Monday, blaming Israel's ongoing invasion of Lebanon.

"Given the continuing crimes of the Zionist regime (Israel) in Lebanon and considering that Lebanon was one of the preconditions for the ceasefire and that this ceasefire has now been violated on all fronts, including Lebanon, the Iranian negotiating team is suspending dialogues and exchange of texts through mediators," Tasnim reported.

Hezbollah said its fighters were still battling Israeli troops near south Lebanon's Beaufort castle on Monday, a day after Israel said it seized the strategic fortress and troops raised the Israeli flag there.

The European Union on Monday urged Israel to halt its military operation in Lebanon, after Israel seized the strategic Beaufort Castle and said it would resume strikes on southern Beirut.

"We call on Israel to stop its military escalation in Lebanon and to respect Lebanon's sovereignty and territorial integrity," EU spokesman Anouar El Anouni said.

Iranian Foreign Minister Abbas Araghchi said Monday that attacking Lebanon violates the ceasefire "on all fronts," warning that "the U.S. and Israel are responsible for the consequences of any violation," after Israeli officials threatened to bomb Beirut's southern suburbs.

"The ceasefire between Iran and the US is unequivocally a ceasefire on all fronts, including in Lebanon. Its violation on one front is a violation of the ceasefire on all fronts. The US and Israel are responsible for the consequences of any violation," Araghchi wrote on X.