Boris Johnson will appear on Donald Trump's favourite television show in an effort to speak directly to the US president amid fears he will scrap the Iran nuclear deal.
The foreign secretary is on a two-day visit to Washington where he is mounting last-ditch efforts to save the international agreement, which has eased sanctions on Tehran in exchange for curbs on its nuclear programme.
Mr Trump has been highly critical of the nuclear deal, describing it as "disastrous" and the "worst ever", and has given Britain and its allies until Saturday to fix the agreement, which he believes is too lenient.
As well as meeting senior figures in the Trump administration, Mr Johnson will also try to reach the president during an appearance on Fox & Friends on Monday, a right-wing morning news programme which Mr Trump frequently tweets about.
Scrapping the deal could prompt a nuclear arms race, with Iran "dashing for a bomb", the foreign secretary argued in an opinion piece for the New York Times, which Mr Trump is also known to read.
Writing in the newspaper, Mr Johnson said: "What has been gained from the nuclear deal? Imagine all the mutually contaminating civil wars and internecine conflicts that rage across the Middle East today.
"Then turn the dial and add the possibility of a regional nuclear arms race triggered by Iran dashing for a bomb. That is the scenario which the agreement has helped to prevent."
He acknowledged that the deal had weaknesses but said he was "convinced they can be remedied" by British, French and German diplomats who have been working with US counterparts for weeks to save the deal.
The agreement had put restrictions on Iran's nuclear programme and "now that these handcuffs are in place, I see no possible advantage in casting them aside", Mr Johnson added.
The president gave allies until Saturday to fix his concerns with the 2015 deal - signed by Britain, Germany, Russia, China, the US, and France, with Iran - which include the failure to address Iran’s ballistic missile programme and the terms of how inspectors visit suspected sites.
UK ambassador to the US, Sir Kim Darroch, said efforts were ongoing to "find some language, produce some action that meets the president's concerns".
He told CBS: "We have been talking at senior official level to the administration with our French and German colleagues for several weeks now.
"We think we're making progress. We haven't got there yet. We have a few days left to see if we can find a way through."
Sir Kim said that "Plan A is that the US stays in the deal" but "we are looking at all eventualities".
Mr Johnson is due to meet vice president Mike Pence and Mr Trump’s hawkish new national security adviser John Bolton on his visit to Washington.
He was also expected to discuss North Korea, ahead of President Trump’s planned meeting with Kim Jong-un, and the situation in Syria.
