The first round of reimposed USA sanctions targeting Iran's aviation and auto industries, as well as its banking system snapped back on Tuesday.
Donald Trump claimed they were "the most biting ever imposed" and warned that in November, sanctions would "ratchet up to yet another level" with an embargo on Iranian oil and blanket sanctions on Iranian banks.
In November, a second batch of potentially more damaging sanctions will be reinstated on Iran's port operators, and the energy, shipping, and shipbuilding sectors.
Despite the political will to hold firm, many large European firms such as German automaker Daimler are leaving Iran for fear of United States penalties.More news: Pentagon restricts use of GPS-enabled fitness trackers
Gholamali Khoshroo argues in a commentary published by the Guardian on Wednesday that by abrogating a multilateral 2015 nuclear deal and imposing new sanctions on foreign companies doing business with Iran, the Trump administration is also reneging on UNSC resolution 2231.
The Turkish minister described the USA sanctions as "unilateral".
"China has consistently opposed unilateral sanctions and long-armed jurisdiction", the Chinese foreign ministry said in a faxed statement to Reuters, responding to questions on the new USA sanctions and Trump's threats on firms doing business with Iran.
European countries, hoping to persuade Tehran to continue to respect the deal, have promised to try to lessen the blow of sanctions and to urge their firms not to pull out. But that has proved hard: European companies have quit Iran, arguing that they can not risk their USA business.
Among large European companies that have suspended plans to invest in Iran are France's oil major Total and its big carmakers, PSA and Renault.More news: Category 3 Hurricane Hector roars in Pacific far from land
Turkey, however, said it would continue to buy natural gas from Iran. "Our crews that are on board our ships are well rehearsed, well prepared by the U.S. Navy when they come into our area", Votel said.
US officials have said in recent weeks that they aim to pressure countries to stop buying oil from Iran in a bid to force Tehran to halt its nuclear and missile programs and involvement in regional conflicts in Syria and Iraq.
Rouhani hinted last month that Iran could block the Strait of Hormuz, a major oil shipping route, if the USA attempted to stop the Islamic Republic's oil exports.
The Rodong Sinmun also ran a story on Wednesday appearing to support Iran's own recent pushback against the USA, saying the "threats and sanctions regime can not affect the will and spirit of the Iranian people".
His visit to Iran is the first by a high-ranking DPRK delegation since August past year, when President of the Presidium of the Supreme People's Assembly Kim Yong Nam and vice foreign minister Choe Hui Chol spent several days in the country.More news: New York Congressman Arrested On Insider Trading Charges