White House national security adviser John Bolton said USA sanctions on European companies that maintain business dealings with Iran were "possible", while Secretary of State Mike Pompeo said he remained hopeful Washington and its allies could strike a new nuclear deal with Tehran.
France urged Europeans to stand up to U.S. President Donald Trump over the Iran nuclear deal and not act as "vassals", as the region scrambles to save the 2015 accord and billions of dollars in trade.
Last week, President Trump withdrew the U.S. from participation in the Iran nuclear deal and announced a restart to the sanctioning process.
"China is highly concerned with the direction of the Iranian nuclear issue and is willing to maintain communication with all relevant parties, including Iran", Geng Shuang, spokesman for China's ministry of Foreign Affairs, said ahead of Zarif's arrival.
Iran has said it is preparing to resume "industrial-scale" uranium enrichment "without any restrictions" unless Europe can provide solid guarantees that it can maintain trade ties despite renewed United States sanctions.
"The most significant group are the larger European companies that have relatively extensive interests in the U.S., that probably export to United States market, they probably have interactions with American banks, with American stock exchanges - and they're obviously the most exposed group to potential USA sanctions".
But Secretary of State Mike Pompeo said Washington was keen to thrash out a more wide-ranging deal with its allies as Trump said Iran had been "trying to take over" the Middle East since the nuclear agreement was signed.
The deal was negotiated between Iran and the five permanent members of the UN Security Council - Britain, China, France, Russia and the United States - plus Germany.More news: Another Terror Attack in Indonesia — Travel Warning
The US decision to walk away from the 2015 nuclear deal also threatens to cut off a chunk of the world's crude oil supply, which is sending oil prices up.
That being said this possibility seems very remote after the USA withdrawal from the nuclear deal.
With regard to oil prices and fundamentals, most analysts agree that the gravity of the effect USA sanctions against Iran will have is questionable. "They will never abandon the USA for us", said housewife Poormoslem at a protest rally against Trump on Friday.
Trump's move to ditch the nuclear deal has infuriated Washington's allies in Europe as well as China and Russian Federation. "Who will buy Iranian oil and who will side with Mr Trump".
"The holy system of the Islamic Republic will step up its missile capabilities day by day so that Israel, this occupying regime, will become sleepless and the nightmare will constantly haunt it that if it does anything foolish, we will raze Tel Aviv and Haifa to the ground", he said, according to state television.
Iran's president is also pushing for the deal to continue. "Do they want to do business with a threat?" he asked.
"We have experienced a break in German-American, in European-American relations", German Chancellor Angela Merkel told a labor union congress in Berlin on Tuesday.
"Remember how badly Iran was behaving with the Iran deal in place", he said.
In his television appearance Sunday, Mr. Pompeo also expanded on his comments Friday that the US would help North Korea achieve economic prosperity if it gave up its nuclear arsenal. The impact will be on those remaining in the Iran nuclear deal, especially the nations which, under UN rules, are allowed to buy Iranian crude oil but could be stymied by sanctions via the USA banking system.