"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".
Despite opposition from European allies, US President Trump in May pulled the United States out of a deal between world powers and Tehran under which worldwide sanctions were lifted in return for curbs on Iran's nuclear program.
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.
Iraq's Prime Minister Haider al-Abadi is to visit top trading partners Turkey and Iran next week, an official said Saturday, days after Washington slapped new sanctions on Tehran and piled economic pressure on Ankara.
In a tweet posted earlier this week, President Donald Trump wrote: "Anyone doing business with Iran will NOT be doing business with the United States". The second batch will be restored on November 4.
Any of those lots, he explained, can be used for nearly a year and, therefore, we have fuel for the Tehran reactor, he said, for at least seven or eight years. "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".
Pakistan reiterates 'strong support' for Turkey after United States sanctions
He also took higher interest rates off the table and said Turkey wouldn't accept an worldwide bailout. On Sunday, Germany's Economy Minister Peter Altmaier criticized the USA sanctions against Turkey .
On Tuesday, Foreign Office minister Alistair Burt said that the USA had "not got this right" and Britain was ready to stand up to Trump, telling the BBC: "Sometimes you need to take a stand against friends".
On Monday, Trump ordered all nuclear-related sanctions that were removed under the deal to be reinstated immediately.
The US ambassador to London has said the United Kingdom should join Donald Trump in adopting a hardline attitude towards Iran.
Britain's May might face a party leadership challenge later in the year, possibly from Boris Johnson, the former foreign minister who says she should be more like Trump.
Since then, Britain, France and Germany have sought to keep the deal alive, while Trump has prepared new sanctions, saying a broader and more balanced deal is needed.