Iran and allies vow revenge

Iranian Supreme Leader Ali Khameini, who was close to Soleimani, has vowed "severe revenge" awaits the general's killers.

"Severe revenge awaits the criminals whose dirty hands were tainted with his blood and the blood of all the martyrs of last night's incident," he said, announcing three days of mourning.

"The martyr, Soleimani, was an international resistance figure, and all those who loved him are calling for revenge for his blood."

Javad Zarif, Iran's foreign minister, called the assassination an "act of international terrorism".

"The US' act of international terrorism, targeting & assassinating General Soleimani-THE most effective force fighting Daesh [Islamic State], Al Nusrah, Al Qaeda et al-is extremely dangerous & a foolish escalation," Zarif said.

Hezbollah leader Hassan Nasrallah said: "Meting out the appropriate punishment to these criminal assassins... will be the responsibility and task of all resistance fighters worldwide."

Meanwhile a Syrian foreign ministry spokesperson said the killing was "a serious escalation of the situation" in the Middle East and likened the US' methods to those "of criminal gangs".