"If you can kill a disbelieving American or European -- especially the spiteful and filthy French -- or an Australian, or a Canadian... including the citizens of the countries that entered into a coalition against the Islamic State (ISIS), then rely upon Allah, and kill him," said Abu Mohammed al-Adnani, the group's spokesman, in a message released in multiple languages.
"Kill the disbeliever whether he is civilian or military," he said.
The United States and France are carrying out airstrikes against ISIS targets across Iraq and are seeking to build an international coalition against a group increasingly perceived as a global threat.
The jihadists, who have declared a "caliphate" straddling Iraq and Syria, control swathes of territory in both countries.
The group is regarded as the most violent and powerful in modern jihad. It has executed hundreds of Iraqis and Syrians, as well as foreign hostages, and its brutal campaign has forced more than a million from their homes.
Adnani's message -- which was released in an Arabic audio recording, together with transcripts in English, French and Hebrew -- gave instructions on how the killings could be carried out without military equipment.
"Smash his head with a rock, or slaughter him with a knife, or run him over with your car, or throw him down from a high place, or choke him, or poison him," the ISIS spokesman said.
Adnani also praised militants in Egypt's Sinai Peninsula, calling on them to "cut the throats" of those fighting for President Abdel Fattah al-Sisi.
"O America, O allies of America, and O crusaders, know that the matter is more dangerous than you have imagined and greater than you have envisioned," he said.
"We have warned you that today we are in a new era, an era where the (Islamic) State, its soldiers, and its sons are leaders not slaves."
(AFP)