Hezbollah left the door open to a negotiated ceasefire on Tuesday after Israeli forces made new incursions in Lebanon, and Israel's defence minister said another senior official from the Iran-backed group appeared to have been killed.

In what could be the latest in a series of major blows to Hezbollah, Israeli Defence Minister Yoav Gallant said it appeared the replacement for slain Hezbollah leader Sayyed Hassan Nasrallah had been "eliminated".

Hashem Safieddine, a top Hezbollah official, was widely expected to succeed Nasrallah. Safieddine has not been heard from publicly since an Israeli airstrike late last week.

"Hezbollah is an organisation without a head. Nasrallah was eliminated, his replacement was probably also eliminated," Gallant told officers at the Israeli military's northern command centre, in a brief video segment distributed by the military.

"There's no one to make decisions, no one to act," he said, without providing further details.

In a televised speech, Hezbollah deputy leader Naim Qassem, said he supported attempts to secure a truce, and for the first time did not mention the end of war in Gaza as a pre-condition to halting combat on the Lebanon-Israel border.

Qassem said Hezbollah supported attempts by Speaker of Parliament Nabih Berri, a Hezbollah ally, to secure a halt to fighting, which has escalated in recent weeks with the Israeli ground incursions and the killing of top Hezbollah leaders.

"We support the political activity being led by Berri under the title of a ceasefire," Qassem said in his 30-minute televised address.

It was not clear whether this signalled any change in stance, after a year in which the group has said it is fighting in support of the Palestinians during the Israel-Hamas war in Gaza, and would not stop without a ceasefire there.

Speaking in front of curtains from an undisclosed location, Qassem said the conflict with Israel was a war about who cries first, and Hezbollah would not cry first. The group's capabilities were intact despite "painful blows" from Israel.

"We are striking them. We are hurting them and we will prolong the time. Dozens of cities are within range of the resistance's missiles. We assure you that our capabilities are fine," said Qassem. (Reuters)