Trump at the time responded to Rouhani with an all-caps tweet.
In several videos posted to social media over the past week, crowds of dissidents are heard chanting, "Death to the dictator" as the United States prepared to reinstate sanctions on the country following President Donald Trump's exit from the worldwide nuclear deal in May.
The surprise meeting comes as US-Iran relations are further strained amid the first wave of the US reinstated sanctions coming into force.
The US is now also pushing Pyongyang to scrap its nuclear capabilities after Trump and North Korea's leader Kim Jong Un agreed a vague commitment to "denuclearisation of the Korean Peninsula" at their landmark summit in June.
"We want to see a much broader retreat by Iran from their support for global terrorism, their belligerent military activity in the Middle East and their ballistic missile, nuclear-related programs", National Security Advisor John Bolton told Fox News.
The US has recently impose crippling sanctions on both countries in respect of their nuclear programmes.More news: Mourinho hopes World Cup players can feature in opener
Ri was also quoted as describing the sanctions against Iran as "inappropriate and contrary to global standards". These are the most biting sanctions ever imposed, and in November they ratchet up to yet another level.
"Our policy is based on a clear-eyed assessment of the Iranian dictatorship, its sponsorship of terrorism, and its continuing aggression in the Middle East and all around the world", the president said. "Just ask EU, Russia, China & dozens of our other trading partners", Zarif remarked.
"The countries now the USA is negotiating with have told Washington that they will continue their oil purchases from Iran", he explained. They had also proposed setting up accounts for the Central Bank of Iran in their national banks, he added.
Mr Zarif said European powers - who say the nuclear deal is working - were asking other countries to continue buying Iranian oil or even start doing so when the next batch of United States sanctions take effect.
"As a result of these measures, the U.S. has been isolated". "Chaos in Iran -as we have experienced in Iraq or Libya- would destabilize an already troubled region even more".
In a blistering criticism of the leader of the Islamic Revolutionary Guards Quds Force, the four-star U.S. general in charge of USA military of operations in the Middle East said Qasem Soleimani is behind much of Iran's destabilizing activities in the region.