Boris Johnson invited Iran’s Hassan Rouhani to London, as he called for “progress” on the cases of British citizens detained in Tehran.
The Prime Minister’s meeting with the president at the United Nations General Assembly in New York on Tuesday comes amid heightening tensions with the Islamic republic.
Mr Johnson blamed the attacks on Saudi Arabian oil facilities on Tehran, and called the Iranian nuclear pact a “bad deal” as he tipped Donald Trump as the “one guy” who could negotiate a new one.
A number of British-Iranian dual nationals are also being held in Tehran on highly-disputed allegations, including mother Nazanin Zaghari-Ratcliffe.
The PM raised his “deep concern” about Iran’s destabilising activities in the region and confirmed his support for the Iran nuclear deal during the meeting, according to Downing Street.
And Number 10 said he “stressed the need for dialogue, including on a comprehensive successor deal”.
At the beginning of the meeting, Mr Johnson invited Mr Rouhani to London “where we can discuss things more”.
“But there are other issues also I wish to raise with you and we retain serious concerns about the detention of dual nationals in Tehran and we are looking forward to make progress on that,” he added.
The PM said his visit to Tehran in 2017 as foreign secretary was “very productive but so far inconclusive”, adding: “I think we still have a lot of progress to make.”
Ms Zaghari-Ratcliffe is more than half-way through a five-year sentence over spying charges, allegations she vehemently denies.
Her husband, Richard Ratcliffe, had called on the PM to tell Mr Rouhani that “enough is enough” and that he must free the mother immediately.
Mr Johnson’s meeting with the Iranian leader came two days after he formally accused Tehran of being responsible for the Aramco attacks, which forced up oil prices.
The attribution of responsibility – which Tehran disputes – earned him a swift rebuke from Iran.
The PM went on to criticise the Joint Comprehensive Plan of Action (JCPoA) as having “many defects”, in a break from previous UK policy.
But he went on to reaffirm British commitment to the JCPoA in a joint statement with France and Germany, as they blamed Iran for the Saudi attacks in a display of unity.
The PM’s meeting came immediately after Mr Rouhani met with French President Emmanuel Macron, and the three spoke briefly in the same room in the Millennium Hilton hotel opposite the UN.
Mr Macron said it would be a “lost opportunity” if US President Donald Trump does not meet Mr Rouhani before he leaves the states.
Addressing Mr Rouhani, Mr Johnson said: “I think I agree with Emmanuel. You need to be on the side of the swimming pool and jump at the same time.”