Iran Vows 'Whatever It Takes' Retaliation After US Strike Kills Khamenei

Speaking to ABC News, Araghchi rejected Washington's justification outright.

"What the United States is doing is an act of aggression. What we are doing is the act of self-defence," he said.

The statement lays out Iran's diplomatic and legal position - casting the United States as the aggressor and framing Tehran's response as legitimate under international law.

Araghchi offered no hint of de-escalation.

"We are defending ourselves, whatever it takes," he said.

The language signals open-ended retaliation authority. Araghchi did not outline a timeline. He did not specify targets. He did not indicate readiness for negotiations.

His remarks come as US officials describe an ongoing campaign aimed at degrading Iran's missile infrastructure. But Araghchi did not acknowledge damage to Iran's military capabilities. Nor did he suggest instability within the political system following Khamenei's death.

American lawmakers, meanwhile, signalled that operations would continue.

Senate Intelligence Committee Chairman Tom Cotton said the coming days would see "a methodical and systematic focus on Iran's missiles, its missile launchers, and ultimately its missile manufacturing capability."

He also warned, "There's no doubt, though, that Iran is going to continue to target our bases in the region, our Arab friends, and Israel."

Other US leaders questioned the intelligence basis of the strike. Senator Mark Warner said, "There was no imminent threat to the United States."

He added, "We have had very little visibility into what happens next after the supreme leader is eliminated."

Senator Adam Schiff also criticised the scale of the action, saying, "There was simply no basis to go in with this massive military campaign, with the goal of regime change."

With its supreme leader dead, Iran now enters a period of transition. Under its constitution, the Assembly of Experts is responsible for selecting a successor, though the Islamic Revolutionary Guard Corps holds significant influence within the system.

For now, Tehran's message remains defiant. Araghchi's words leave little ambiguity: Iran does not view itself as defeated - and any response, in his phrase, will come "whatever it takes."

- IANS