The UK and Iran are in discussions over a £400m debt that the UK owes, foreign office minister James Cleverly has said – but the talks are not linked to the detention of Nazanin Zaghari-Ratcliffe.
The UK owes the money for failing to deliver tanks Iran bought in the 1970s.
British-Iranian national Mrs Zaghari-Ratcliffe, who is in jail in Iran, believes she has been imprisoned as leverage for the debt.
“There are two entirely separate issues,” the prime minister said.
Speaking to reporters during a visit to Hartlepool, Boris Johnson said ministers were doing “everything we can to look after the interests of Nazanin and all the very difficult dual national cases we have in Tehran”.
The case of Mrs Zaghari Ratcliffe made headlines again in recent weeks after she was sentenced to another year in prison, just weeks after she reached the end of a five-year sentence. She was first jailed in Tehran in 2016 on spying charges, which she has always denied.
Her husband, Richard, maintains she is being used as a bargaining chip in the dispute over the unpaid debt, as well as leverage in talks over the nuclear deal between Iran and world powers.
On Sunday, Iranian state TV suggested the UK had paid the £400m debt – but the UK government said nothing had changed.
Foreign Office minister Mr Cleverly said: “The situation with regards to the… military contract from the 1970s which has dragged on for decades, those negotiations are ongoing. They have been for a long while, sadly, but they are ongoing.”
Asked if the talks were getting anywhere, Mr Cleverly said: “There’s a legal process tied up with this as well. Iran most recently stepped away from that legal process which has of course delayed things.
“We are looking at ways of resolving what has been a multi-decade long problem.
“The reports that we had over the weekend linking that work with the incarceration and the arbitrary detention of British dual nationals I think was completely inappropriate – they are separate issues, one massively predates the other.”
He said the imprisonment of dual nationals in Iran “should be unlinked to the multi-decade long dispute with regard to the tanks”.