The extraordinary move makes the first time in history the United States has labelled another nation’s military as a terrorist organisation. Iran swiftly retaliated by declaring US forces in the Middle East as terrorists, according to Iran state news. This is the latest in the increasingly fraught relationship between the nations, and threatens deepening tensions further.
Washington-Tehran tensions have been rising since Donald Trump withdrew the US from the Iran nuclear deal.
This latest move, labelling the Revolutionary Guard Corps (IRGC) as a foreign terrorist organisation, will allow the US to impose further sanctions on Iran.
The United States has already blacklisted dozens of entities and people for affiliations with the IRGC, but not the organisation as a whole.
READ MORE: Donald Trump MOCKED by US journalist ahead of Mueller statement – ’It sows confusion’
Mr Trump’s statement came on Monday, and said: “This unprecedented step, led by the Department of State, recognises the reality that Iran is not only a State Sponsor of Terrorism, but that the IRGC actively participates in, finances, and promotes terrorism as a tool of statecraft.”
He added the move was meant to “significantly expand the scope and scale” of pressure on Iran.
The President said: “If you are doing business with the IRGC, you will be bankrolling terrorism.”
The State Department said the measure will take effect in one week’s time.
What has the response been?
US Secretary of State Mike Pompeo and National Security Adviser John Bolton have championed this decision and came out in strident support.
Mr Pompeo told reporters on Monday the US will continue to sanction and pressure Iran to “behave like a normal nation” and urged America’s allies to take similar action.
He said: “The leaders of Iran are not revolutionaries and people deserve better. They are opportunists.”
In a later tweet, he added: “We must help the people of Iran get back their freedom.”
But not all US officials were so supportive.
Joint Chiefs of Staff Chairman Gen Joe Dunford, had expressed concerns about troop safety, the Wall Street Journal reported.
Military officials cautioned the designation could incite violence against US forces in the Middle East without severely impacting Iran’s economy.
The Central Intelligence Agency had also reportedly opposed the move.
And in Iran, the announcement was met with retaliation of equal measure: Iran’s national security council declared US Central Command (Centcom) a terrorist organisation.
The move came after Foreign Minister Javad Zarif wrote to President Hassan Rouhani urging such a response, state news channel IRINN said.