CNN | Fred Pleitgen: Iran's Foreign Minister Javad Zarif called US President Donald Trump's decision to order the drone strike that killed the country's top military commander an act of "state terrorism" in an interview with CNN Tuesday.

Zarif said the Trump administration's decision to abandon the nuclear deal Tehran negotiated with world powers and embrace hardline policies against Iran "destroyed stability" in the Middle East, and he warned of worse to come if the US did not reverse course.

"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."

Zarif was referring to a tweet Trump sent Saturday in which the President said that if Iran strikes any Americans or American assets, the United States has 52 Iranian sites targeted -- a reference to the number of Americans taken hostage in the 1979 revolution -- "some at a very high level & important to Iran & the Iranian culture," he wrote.

Iran's top diplomat said those comments showed Trump "has no respect for international law and is prepared to commit war crimes -- attacking cultural sites is a war crime."

The interview came as Iran's parliament voted unanimously for a motion declaring all US forces as "terrorists" on Tuesday, according to Iran's state-news agency IRNA. The vote took place during the country's parliamentary session Tuesday, IRNA reported. After the plan was approved, delegates chanted, "Death to America."

Tensions between Iran and the US have escalated since Qasem Soleimani, the head of Iran's powerful Quds Force, was killed on Friday.

Images from inside Iran showed streets packed with mourners clad in black to bid farewell to Soleimani, who was revered as a hero and is now being celebrated as a martyr. Iranian state television said millions of people attended his funeral, although this figure has not been verified.

"President Trump, after watching the crowds yesterday, must stop threatening these people who will be further enraged by his threats -- his threats will not frighten us," Zarif said.
He added: "A war was started a long time ago by the United States, the United States destroyed stability in this region, the United States undermined security in this region."

Zarif was a key player in the negotiations that led to the 2015 nuclear deal known as the Joint Comprehensive Plan of Action (JCPOA).

Under the deal, the Iranian government agreed to strict limits on its nuclear program in exchange for relief from economic sanctions. Trump withdrew the US from the deal in 2018, arguing that it was too lenient on Tehran, and reenacted punitive measures that have strangled the Iranian economy.

Zarif claimed that by leaving the deal, Trump threw the Middle East into chaos."What is important is for the Trump regime to realize is that everything in this region was improving following the JCPOA," Zarif said.

"We saw normal elections in Iraq, normal elections in Lebanon ... we had the reduction of tensions in Syria ... what happened? The United States started a maximum pressure campaign, terrorizing the Iranian people, making it difficult for Iranians to even get food and medicine."

CNN's James Griffiths and Joshua Berlinger contributed to this report