"I am not in the business of making threats, but the book is not closed", Zarif said during a Council on Foreign Relations virtual event when asked about Iran retaliating over Soleimani’s assassination.
Zarif added that the Iranian general was a hero to many in the region because of his role in combating terrorists, most notably Daesh*, and many still want answers for his death.
On 3 January, Soleimani, one of the most prominent military figures in Iran, and several other members of the Iranian Revolutionary Guard Corps were killed in a US drone strike on the outskirts of Baghdad. The killing prompted Tehran to launch missile strikes on US bases in Iraq.
After the assassination, the Iraqi parliament voted to expel all the foreign forces from the country and suspend NATO operations.
*Daesh (also known as ISIS/ISIL/IS) is a terrorist group banned in Russia