The Islamic cleric then threatened to further escalate Israel's war with Hamas as it nears the one-month mark.
But in televised remarks - his first since the Palestinian militants’ deadly 7 October incursion into southern Israel - Nasrallah stopped short of announcing that Hezbollah would fully enter the war, a move that would have devastating consequences for both Lebanon and Israel.
The United States, Israel's strongest backer, has warned Hezbollah and its patron Iran against entering the fray and has sent warships to the Mediterranean, a move Nasrallah said "will not scare us.”
Hezbollah is prepared for all options, he declared, “and we can resort to them at any time.” The fighting would “not be limited” to the scale seen so far, he added. In recent weeks, Hezbollah has fired rockets across the border daily, mainly hitting military targets in northern Israel, but it has a substantial arsenal capable of hitting anywhere in Israel and thousands of battle-hardened fighters.
Nasrallah's speech had been widely anticipated throughout the region as an indication whether the Israel-Hamas conflict would spiral into a regional war.
“Some say I’m going to announce that we have entered the battle," Nasrallah said Friday. "We already entered the battle on Oct. 8.” He argued that Hezbollah's cross-border strikes have pulled away Israeli forces that would otherwise be focused on Hamas in Gaza.
Thursday saw the most significant escalation on the Israel-Lebanon border since the war started, with Hezbollah firing off a barrage of mortar shells and anti-tank missiles and, for the first time, suicide drones.
Nasrallah criticized the strong US backing of Israel's bombardment of Gaza that has killed more than 9,000 people, mostly civilians. While US officials in recent days have pushed more publicly for protecting civilians in Gaza, they have yet to call for a cease-fire.
The Hezbollah leader said President Joe Biden had made a “fake argument that Hamas cut off children’s heads (without) evidence, but stayed silent for the thousands of children in Gaza who were decapitated and their limbs were torn apart” by Israeli bombing.
Nasrallah praised the 7 October Hamas' incursion into Israel, when the militants attacked farming villages, towns and military posts, killing more than 1,400 people, while Israeli forces were slow to respond.
It was “proof that Israel is weaker than a spider’s web” and one month into the war, it “has not been able to make any achievement,” Nasrallah said.
He insisted that Hamas had planned the attack in secrecy and that Hezbollah had no part in it. “This great, large-scale operation was purely the result of Palestinian planning and implementation,” Nasrallah said.
Faced by a relentless aerial bombardment and now a ground incursion by Israeli forces in Gaza, Hamas leaders have been pushing - sometimes publicly - for Hezbollah to widen its involvement in the war. Nasrallah met last week in Beirut with senior Hamas official Saleh al-Arouri and with Ziad Nakhaleh of the allied group Islamic Jihad.
However, Hezbollah officials have avoided publicly setting a specific red line, saying vaguely that they would join the war if they see that Hamas is on the verge of defeat. Instead, Hezbollah has taken calculated steps to keep Israel’s military busy on its border with Lebanon, but not to the extent of igniting an all-out war.
The Israeli military said seven of their soldiers and one civilian had been killed on the northern border as of Friday. More than 50 Hezbollah fighters and 10 militants with allied groups, as well as 10 civilians, including a Reuters journalist, have been killed on the Lebanese side of the border.
Israel considers the Iran-backed Lebanese Shiite militant group its most serious immediate threat, estimating that Hezbollah has around 150,000 rockets and missiles aimed at Israel, as well as drones and surface-to-air and surface-to-sea missiles.
But a full-on conflict would also be costly for Hezbollah, which fought a 34-day war with Israel in 2006 that ended with a draw - but not before Israeli bombing reduced swaths of southern Lebanon, the eastern Bekaa Valley and Beirut’s southern suburbs to rubble.
A new all-out war would also displace hundreds of thousands of Hezbollah’s supporters in southern Lebanon and cause wide damage at a time when Lebanon is in the throes of a historic four-year economic meltdown.