In an interview published on Wednesday, Anas Sharkas, also known as Ali Abu Al Shishani, accused the Lebanese government of being an accomplice to Hezbollah, which he said has "taken Iran as its god".
The announcement was made public after weeks of fighting between the Lebanese army and jihadists on the border between Lebanon and Syria.
In an interview with the Lebanese daily Al-Akhbar, Sharkas called on jihadists from both the Islamic state and the al-Nusra Front groups to move their fight inside Lebanon.
Al-Akhbar stated that the interview took place two months ago on the outskirts of Arsal, where the two groups have held a number of Lebanese servicemen hostage.
The newspaper did not say why it was only published yesterday.
Sharkas told Al-Akhbar that the Beirut government is weak and subservient to Hezbollah, which is aligned with the government of Syria's President Bashar al-Assad.
He accused Hezbollah of massacring the jihadists’ men, women and children while the party and their supporters enjoy safety, adding that his supporters will only succeed by fighting them inside Lebanon.
Sharkas recently announced his defection from the Al-Qaeda-aligned Al-Nusra Front to IS in a video.
This was posted as a response to his wife Olga al-Oqaili's detention by Lebanese security after she attempted to cross into the country on fake documents.
In the video Sharkaes threatened to attack Lebanon and expand kidnappings to women and children following his wife's arrest.
The Al-Nusra Front executed one hostage, police officer Ali Bazzal, on Friday, after the news broke of Al-Oqaili's arrest along with the former wife of the IS leader, Abu Bakr al-Baghdadi.
Sharkas also called on the two jihadist groups to unite in battle, despite long-term rifts between them.
Al-Oqaili was recently transferred to Lebanon's General Security Agency, raising hopes that she will be exchanged for the group of servicemen captured by both militias last August.