Analysts say that renewed US sanctions would impact European companies that have business in Iran. European governments are promising to safeguard the interests of their companies.

European trade and investment have flowed into Iran since the sanctions were lifted in January 2016. But businesses have been told to wind down their operations in Iran because of the new sanctions set to be imposed by the United States.

ZHANG HE BERLIN "Germany is one of Iran's largest trading partners and the impact on its business seems immediate. The newly appointed US ambassador to Germany Richard Grenell has called on all German companies to immediately stop their operations with Iran."

About 21 companies from five European countries have businesses in Iran, including Siemens, Volkswagen and Airbus. The question for them is how they can maintain their businesses and what support they will need from the EU to continue.

CORNELIUS ADEBAHR, ASSOCIATE FELLOW GERMAN COUNCIL ON FOREIGN RELATIONS "If they have business in the United States, they face the prospect of the sanctions against the business arm in the United States if they stay in Iran. So, industry-wide sanctions would make it illegal for them under U.S. law to engage in the business. The question is can they and the European governments find a way to only abide by the EU law because they are European companies. This is something that needs to be worked out in the coming months."

European governments have promised to protect the interests of their companies. That's as the US Treasury Department says there will be a "wind down" period of 90 to 180 days for existing Iran contracts.

CORNELIUS ADEBAHR, ASSOCIATE FELLOW GERMAN COUNCIL ON FOREIGN RELATIONS "It is not for the benefit of European cooperation, but it is part of the deal, Iran is allowed to reintegrate to the world economy. And it is the benefits they would expect for what they have been doing under the deal, which means restraining their nuclear program. So, it is not only primarily losing business opportunities for Europe which is worrisome but the West in general doesn't fulfill its obligations under the deal if it doesn't provide trade opportunities."

What comes next will be a lot of talks and negotiations, not only asking Iran to stay in the deal, but also to maintain the economic exchanges between Europe and Iran. ZH, CGTN, Berlin.