By threatening to target Iranian cultural sites if Tehran responds to the airstrike which killed general Qasem Soleimani, US President Donald Trump showed the international community that "he has no respect for international law and is prepared to commit war crimes -- attacking cultural sites is a war crime," Iran's top diplomat said Tuesday.

Speaking to CNN's Fred Pleitgen in Tehran, Iranian Foreign Minister Javad Zarif said that Trump's actions and statements showed "he doesn't care about international law."

The strike against Soleimani while he was in Iraq was an act of "state terrorism," Zarif added, reiterating that Tehran will mount a response.

"This is an act of aggression against Iran, and amounts to an armed attack against Iran and we will respond. But we will respond proportionally not disproportionally," he said. "We will respond lawfully, we are not lawless people like President Trump."