Speaking in an interview with al-Mayadeen TV channel on Sunday, Sheikh Qassem declined to clarify the movement's response to an Israeli attack that killed one of Hezbollah fighters in Syria last week.

"Let the Israelis have their own estimations and calculations in this regard," he said.

Hezbollah announced the death of Ali Kamel Mohsen, one of its members, in an Israeli airstrike in Damascus on July 20 and promised retaliation. 

Sheikh Qassem also played down recent Israeli threats, saying there were "mere chest-beating.”

His remarks came after Israel’s minister of military affairs Benny Gantz warned  Syria and Lebanon that they would be held responsible for any attacks against Israel coming from their territory.

“We don’t want any unnecessary escalations, but anyone who tests us will be met by a very high capability to take action, and I hope we won’t need to use it,” Gantz said.

Sheikh Qassem dismissed the prospect of an all-out war with Israel in the next few months.

“Israel’s political confusion and low expectation from war outcomes as well as US President Donald Trump’s quagmire eliminate the possibility of an imminent eruption of the war,” he said. 

But he promised Tel Aviv will be delivered yet another defeat if it launched an aggression.

“If Israel decides to go to war with us, then we will confront them, and the 2006 [Second Lebanon] War will be the model for our response,” Sheikh Qassem said.

The Israeli military went into high alert near the Lebanese border, amid concerns that Hezbollah would conduct a retaliation attack.

Gantz made his threats during a visit to the border between the occupied territories and Lebanon on Sunday, where he said the Israeli regime was “prepared for all possibilities”.

Shortly later, an Israeli spy drone crashed inside Lebanon, according to an Israeli military spokeswoman.

In his interview, Sheikh Qassem also touched on the US harassment of an Iranian passenger plane over Syria, saying Washington wants to wreck a strategic pact between Iran and Syria.

The move by the US warplanes was similar to Israeli tactics in the past, when Israel's aircraft used civilian planes as a shield to draw fire from Syrian air-defense systems.

Iran and Syria signed a "comprehensive" agreement to boost military and defense cooperation on July 8.

On Thursday night, US warplanes operating illegally in Syria conducted aggressive maneuvers dangerously close to an Iranian Mahan Air flight over Syria’s al-Tanf region.

Mahan Air’s Flight 1152 had taken off from Tehran and was en route to the Lebanese capital, Beirut, when the incident happened.