Fortunately today, the USA is more isolated than ever following its withdrawal from the JCPOA, said Rouhani, adding "almost all countries in the world except for a few are standing with us against the United States, and that is the victory of our diplomacy".
Iranian President Hassan Rouhani said the country will continue selling its oil and break the second batch of sanctions the USA administration reinstated since President Donald Trump unilaterally pulled out of the nuclear deal in May.
On Saturday, US Secretary of State Mike Pompeo said the decision to reimpose sanctions was "aimed at fundamentally altering the behavior of the Islamic Republic of Iran".
U.S sanctions on Iranian oil that were lifted as part of the 2015 Nuclear Accord have officially come back into effect today.
The Europeans are working to set up a special payment system that would bypass the U.S. sanctions and discard the dollar in dealings with Iran.
Iranian President Hassan Rohani responded early on November 5 by saying in a speech on state TV that Iran is facing a "war situation".
The measures target Iran's vital energy and banking sectors. Iran is the world's No. 3 oil exporter. Watch as we've already taken more crude oil off the market than any time in previous history.
The deal had seen most global financial and economic sanctions on Iran lifted in return for Tehran curbing its disputed nuclear activity under United Nations surveillance.
'We are in the war situation, ' he said.
Iran's economy has been hit hard, with the country's currency, the rial, plummeting in value, leading to some street protests in Iranian cities.
While now not threatening to resume higher enrichment, in recent months Iranian officials have made a point to threaten that it could resume at any time faster than before.
Pompeo and Treasury Secretary Steven Mnuchin were expected to provide more details on the sanctions at a briefing Monday.
Mr Pompeo said the countries had already made "significant reductions in their crude oil exports" but needed "a little bit more time to get to zero".
The Trump administration has granted exemptions to eight countries to continue importing Iranian oil, without naming them.
Iranian officials, meanwhile, reported a cyberattack targeting the country's communication infrastructure, blaming the purported attack on Israel.
Supreme Leader Ayatollah Ali Khamenei also said Iran's arch-adversary the United States had failed to reassert its domination over Iran since the country's 1979 Islamic Revolution that toppled the US-backed Shah.