Don't ditch Iran deal

British Foreign Secretary Boris Johnson has appealed to US President Donald Trump not to pull out of the Iran nuclear agreement, saying the deal had weaknesses but they could be addressed given time.

Trump has said that unless European allies rectify "flaws" in Tehran's 2015 deal with world powers by May 12 he will refuse to extend US sanctions relief for Iran.

Britain, France and Germany remain committed to the accord as is but to address US concerns they want to open talks on Iran's ballistic missile programme, its nuclear activities beyond 2025 - when key provisions of the deal start to expire - and its role in Middle East crises such as Syria and Yemen.

"It has weaknesses, certainly, but I am convinced they can be remedied," Johnson wrote in an opinion piece for the New York Times. "Indeed at this moment Britain is working alongside the Trump administration and our French and German allies to ensure that they are."

Johnson began a two-day visit to the United States on Sunday to try to convince Trump's administration not to ditch the deal.

Johnson said he saw no advantage in losing the "handcuffs" the deal imposed on Iran's nuclear ambitions and only Tehran would benefit from exiting the deal.

"At this delicate juncture, it would be a mistake to walk away from the nuclear agreement and remove the restraints that it places on Iran," Johnson wrote.

"I believe that keeping the deal's constraints on Iran's nuclear program will also help counter Tehran's aggressive regional behaviour."

Meanwhile, Iran's President Hassan Rouhani yesterday hinted that Iran could remain in its 2015 nuclear deal with world powers even if the United States dropped out but Tehran would fiercely resist US pressure to limit its influence in the Middle East.

"We are not worried about America's cruel decisions ... We are prepared for all scenarios and no change will occur in our lives next week," Rouhani said in a speech broadcast live on state TV.