רכבו השרוף של קאסם סולימאניReuters / Anadolu Agency

Ali Khamenei, Iran's Supreme Leader, mourned Qassem Soleimani's death, promising to enact revenge on the "criminals" and "murderers" who perpetrated it.

Soleimani, tasked with expanding the Islamic Revolution, was dubbed during his lifetime by the Supreme Leader as the 'living martyr of the Revolution' and was considered by many to be the most dangerous man in Iran. He was a shrewd commander who oversaw Iranian operations in Iraq and Syria and personally hurled threats at Israel and the United States.

On Thursday night, Soleimani, head of the Quds Force of the Iranian Revolutionary Guard Corps (IRGC),, was eliminated by the US in a drone strike near the Baghdad International Airport in Iraq.

In a letter to the Iranian nation, Khamenei wrote: "The great revenge awaits the criminals whose filthy hands are dirtied with his blood and the blood of the other martyrs in last night's incident. The Martyr Soleimani was a persona who fought in the global arena, and all those who support the struggle demand to avenge his blood."

"All of the friends, and obviously enemies, must know that the activities in the jihad (holy war - ed.) will continue doubled and redoubled, and that the final victory will belong to the mujahideen (jihadists - ed.) who followed this blessed path. The loss of our dear leader, whose life was sacrificed (in jihad) is bitter for us, but the continuation of the fight and the true and final success will be extremely bitter for the murderers and criminals."

Iranian President Hassan Rouhani said: "Soleimani's martyr's death will make Iran more determined in its opposition to US imperialism, and in the protection of Islamic values."

"Without a doubt, Iran and other peace-loving countries in the area will take revenge," he promised.