Israel continued its bombardment of southern and eastern Lebanon on September 29 amid mounting international warnings of a possible land invasion and regional repercussions, with Tehran warning that "even war" is possible following serious blows to Iran-backed militant group Hezbollah.
Prime Minister Benjamin Netanyahu meanwhile described the assassination of longtime Hezbollah leader Hassan Nasrallah on September 27 as a necessary move toward "changing the balance of power in the region for years to come."
Iranian officials sought an emergency meeting of the UN Security Council and the speaker of Iran's parliament pledged ongoing support to groups confronting Israel.
Iranian Foreign Minister Abbas Araqchi was quoted by the official Fars news agency as saying in New York that "Everyone should be aware that the situation is extremely explosive, and that everything is possible...even war."
UN Security Council permanent members the United States and China urged de-escalation, while Russia warned of "fraught" and "dramatic" consequences for the region.
In his his first statement since Israeli forces and Hezbollah confirmed the death of Nasrallah in massive air strikes in Beirut, Netanyahu said "Nasrallah was not a terrorist, he was the terrorist."
SEE ALSO: Hassan Nasrallah's Death A 'Major Loss' For Hezbollah And Ally IranHezbollah is designated as a terrorist organization by the United States, while the European Union blacklists its armed wing but not its political party. Hezbollah’s political party has seats in the Lebanese parliament.
Israel has reported killing a number of senior Hezbollah leaders, and explosive pager and walkie-talkie attacks that killed dozens and injured many hundreds more earlier this month in Lebanon further eroded the group's operations.
SEE ALSO: Israel's Suspected Attack On Electronic Devices In Lebanon Marks New Phase In Hezbollah HostilitiesNetanyahu accused Nasrallah of killing many Israelis but also hundreds of other countries' nationals, and he said he amplified the dangerous influence and policies of Hezbollah's main sponsor, Iran.
The Lebanese escalation comes as Israel's war in Gaza nears the one-year mark since U.S.- and EU-designated terrorist group Hamas launched a cross-border attack that killed more than 1,200 people in Israel on October 7, many of them civilians.
There are fears of a rapidly expanding conflict that could include an Israeli ground offensive in Lebanon and eventually draw Iran and the United States directly into the fighting.
Israeli officials have acknowledged that a ground invasion of Lebanon is among their potential options.
Lebanese officials said Israeli air strikes there on September 28 killed 33 people and wounded 195.
There were fresh air strikes reported in Beirut early on September 29, including an air strike in northeast Lebanon that reportedly killed 11 people.
Lebanese authorities say 250,000 people there have been displaced by the mounting conflict.
Israel's military also announced that it had killed another Hezbollah leader, Nabil Kaouk, in the ongoing exchanges of fire, although that claim could not be independently verified.
U.S. President Joe Biden said Nasrallah's "death from an Israeli air strike is a measure of justice for his many victims, including thousands of Americans, Israelis, and Lebanese civilians."
He said Washington "fully supports Israel's right to defend itself against Hezbollah, Hamas, the Huthis, and any other Iranian-supported terrorist groups."
Biden also said the United States was enhancing its defense posture in the Middle East "to deter aggression and reduce the risk of a broader regional war."
As speculation continued around whether Israel would send ground troops into its northern neighbor Lebanon, Biden said, "It's time for a cease-fire."
Iranian Supreme Leader Ayatollah Ali Khamenei was reportedly taken to a more secure location in that country. Khamenei declared five days of mourning in Iran for Nasrallah.
Iranian media reported that Israel's September 27 attacks in Beirut had also killed a senior commander of Iran's Islamic Revolutionary Guards Corps (IRGC).
On September 28, Iran's mission to the United Nations reportedly called in a letter for an emergency meeting of the 15-member Security Council.
Iranian Ambassador Amir Saeid Iravani is said to have accused Israel of committing "a flagrant act of terrorist aggression against residential areas in Beirut, using U.S.-supplied thousand-pound bunker busters."
On September 29, official media quoted the speaker of Iran's parliament, Mohammad Baqer Qalibaf, as pledging ongoing Iranian support for groups that "resist" Israel.
"We will not hesitate to go to any level in order to help the resistance," Qalibaf said, adding an accusation that the United States was "complicit" and "has to accept the repercussions."
UN Secretary-General Antonio Guterres said he was "gravely concerned" by the "dramatic escalation" in Lebanon. "This cycle of violence must stop now, and all sides must step back from the brink," Guterres said in a statement. "The people of Lebanon, the people of Israel, as well as the wider region, cannot afford an all-out war."
Security Council member Russia has condemned the killing of Nasrallah as "yet another political assassination" that is "fraught with even greater dramatic consequences for Lebanon and the entire Middle East."
On September 29, China's Foreign Ministry urged all parties, but especially Israel, to act to de-escalate the situation.