Johnson's comments come less than a week after the Trump administration on Tuesday reimposed a raft of sanctions on Iran that affect, among other things, the purchase or acquisition of USA dollars by the Iranian government, the country's auto industry and trade in gold or precious metals.
Woody Johnson, the U.S. ambassador to London, encouraged Britain to stick with the United States and ditch a "flawed" 2015 nuclear deal with Iran even as the European Union openly defied sanctions imposed by the Trump administration.
Trump announced on May 8 that he would abandon the Joint Comprehensive Plan of Action (JCPOA), a landmark nuclear deal between Iran and six world powers - the USA, the UK, France, Russia, China and Germany.
Iran announced on Saturday that it will bring back home a second batch of 20%-enriched uranium which has been kept in Russian Federation under the 2015 nuclear deal to be used in Tehran Research Reactor.
The first phase of the unilateral sanctions came into effect on Tuesday, targeting Iran's purchase of United States dollars, trade in gold and other precious metals as well as its automotive sector. "But we have had discussions with Washington about how we can work together in other ways to curb activity by Iran in the Middle East which concern us".
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Investors need to see serious economic measures and not political ones to prevent things getting completely out of control. Erdogan rejected speculation that Turkey would seek a rescue package from the International Monetary Found.
He added, "America is turning up the pressure and we want the United Kingdom by our side".
In an article for The Sunday Telegraph Mr Johnson told British companies to stop doing business with Iran...
US Ambassador to Britain Woody Johnson said Iran needed to make tangible and sustained changes to behave like a normal country. The UK's trade with Iran was £365million in 2016.
On Monday, Trump ordered all nuclear-related sanctions that were removed under the deal to be reinstated immediately. "We are asking global Britain to use its considerable diplomatic power and influence and join us as we lead a concerted global effort towards a genuinely comprehensive agreement", Johnson added. "We don't sympathize with the sanctions, we don't think they are appropriate, and we don't interact with them, but we are committed to protect our people".
The reimposition of sanctions comes amid protests across Iran, with demonstrators voicing dissatisfaction with a weak economy and financial corruption.