The senior official made the scathing remark about the country’s former rival, just a day after he praised the Middle Eastern nation for meeting its obligations under the landmark nuclear deal.
Mr Tillerson, who made a rare appearance before reporters, blasted the Islamic Republic, saying: “In deed and in propaganda, Iran foments discord.
“An unchecked Iran has the potential to travel the same path as North Korea and take the world along with it.”
He criticised the country’s human rights record, accused the nation of sponsoring terrorists and remained sceptical of their long-term nuclear ambitions, comparing them to Pyongyang’s desire to hold the world to ransom through the threat of nuclear warfare.
The nuclear deal was signed by the US, UK, France, China, Russia and Germany
But he did not indicate the US is looking to pull out of the nuclear deal struck with Tehran under the Obama administration.
Delivering in comments, Mr Tillerson added the Iran nuclear deal was merely “another example of buying off a power who has nuclear ambitions.”
He added: “We just don’t see that that’s a prudent way to be dealing with Iran.
Satellite images show Kim Jong-un escalating nuclear action
Wed, April 12, 2017
New satellite images show in great detail how Kim Jong-un is escalating North Korea's nuclear weapons programme.
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Figure 1. Activity continues at the North Portal
An unchecked Iran has the potential to travel the same path as North Korea and take the world along with it
“The Trump administration has no intention of passing the buck to a future administration on Iran.”
He said the agreement added “only delays” to Iran becoming a fully nuclearised state.
Despite his comments, Mr Tillerson confirmed in a statement Iran was meeting its obligations after Donald Trump ordered an interagency review of the deal to determine whether the US should abandon it.
He did not indicate the US is looking to pull out of the nuclear deal
Agreed nearly two years ago, it was signed by the US, UK, France, China, Russia and Germany and heralded the end of crippling economic sanctions on Iran.
Despite no firm indication the US was looking to reverse the agreement, Mr Tillerson’s assault is indicative of the Trump administration's hostile attitude towards Iran.
Tensions have been strained between the two countries for decades, exemplified by the Iranian hostage crisis of 1979, and they have never fully re-established diplomatic ties.
The move may also be viewed as placating the US’ Middle Eastern allies, notably Israel, Saudi Arabia and the United Arab Emirates.
They have been exerting pressure on the US to crack down on Iran’s growing influence in the region.
Relations have been fraught since Iran appeared to conduct several missile tests since signing the deal, including under Mr Trump’s presidency, flouting UN sanctions.
Mr Trump ordered an interagency review of the deal to determine whether the US should abandon it
Some sources claim the country has conducted as many as 14 ballistic missile launches since the agreement was struck in 2015.
Then national-security advisor, Michael Flynn, was highly critical of Tehran during his short stint in the job.
He confirmed Iran was “on notice” following the missile test shortly after Mr Trump took office, adding a review of the country’s policy was underway.
The US moved to impose fresh sanctions on multiple Iranian entities following the tests, but in a way that would not violate the 2015 agreement.
And the missile tests were seemingly referenced by Mr Tillerson in his comments on Wednesday.
Still highly critical of Iran, the Trump administration has pursued an aggressive stance against its foe, with the country one of six which was subject to an ill-fated travel ban imposed by the president.
The senior official made the scathing remark about the country’s former rival
Mr Trump attempted to curb entry into the US from Syria, Libya, Sudan, Yemen, Somalia and Iran, through a visa ban but was slapped down in the courts.
Despite Mr Trump’s distaste for Iran, it seems unlikely the US will pull out of the landmark deal which Iran sticks to its terms.