Britain has challenged the United States to spell out its vision of a new negotiated settlement with Iran after President Donald Trump pulled out of the 2015 international nuclear deal.
Foreign Secretary Boris Johnson said Britain had no intention of walking away from the deal, known as the JCPOA. He also said Britain would do its utmost to protect UK commercial interests in Iran.
"Now that the Trump administration has left the JCPOA, the responsibility falls on them to describe how they in Washington will build a new negotiated solution to our shared concerns," he told parliament.
"President Trump said himself last night that he is committed to finding a new solution and we should hold him to his word."
Johnson said he had no problem with Trump's goal for a lasting solution to Iran's nuclear threat and other Iranian policies seen as malign by London and Washington, but added: "The question is: how does the US propose to achieve it?"
Throughout his statement, Johnson repeatedly said the JCPOA had delivered on the core goal of preventing Iran from moving towards acquiring a nuclear bomb. He also said the central bargain of the deal, better economic prospects for Iran in return for de-nuclearisation, remained valid.
"We did our utmost to prevent this outcome. From the moment that President Trump's administration took office, we made the case for keeping the JCPOA at every level," he said.
"The US decision makes no difference to the British assessment that the constraints imposed on Iran's nuclear ambitions by the JCPOA remain vital for our national security and the stability of the Middle East.
"For as long as Iran abides by the agreement ... then Britain will remain a party to the JCPOA. Britain has no intention of walking away."
