Hezbollah leader Hassan Nasrallah on Wednesday warned of a "very costly" war "without limits" if the situation at the Lebanon-Israel border escalates into a full-scale conflict.

The speech by the head of the Iranian-backed terror group came a day after the targeted killing of Hamas deputy leader Saleh al-Arouri in Beirut, which was attributed to Israel.

Hezbollah has been waging a low-intensity conflict against Israel since Hamas' Oct. 7 massacre of some 1,200 people in the Jewish state.

"Until now, we are fighting on the [Israel-Lebanon] front with set calculations, but if the enemy [Israel] wages war on Lebanon, our fight will be without limits, rules and regulations, and it [Israel] knows what I mean," the terror chief said.

"Who thinks about engaging in a war with us will regret it, God willing! The war with us will be very, very, very costly. If we have so been so far taking into consideration the Lebanese situation and national interests, if war is waged in Lebanon, the Lebanese national interests require that we engage in the war until the end without regulation."

Jerusalem has not taken responsibility for the strike in the suburb of Dahiya, a Hezbollah stronghold, which also killed six other Hamas operatives. It was the first strike in the Lebanese capital attributed to Israel since the 2006 Second Lebanon War.

Al-Arouri was one of the top Hamas leaders on Israel's target list following the terrorist group's Oct. 7 massacre.

Nasrallah condemned the assassination, saying that "yesterday's crime will not go unpunished," adding that he would give more details about the response in another speech on Friday.

He delivered the video speech to a Hezbollah ceremony in Dahiya held to mark the fourth anniversary of the U.S. assassination in Baghdad of Iran's Quds Force commander Gen. Qassem Soleimani and militia leader Abu Mahdi al-Muhandis.

This JNS.org report was republished with permission from Jewish News Syndicate.