Boris Johnson has landed in Iran to discuss the future of imprisoned British-Iranian woman Nazanin Zaghari-Ratcliffe.
The UK foreign secretary, who is set to call for the release of the 37-year-old mother-of-one on humanitarian grounds, will express "grave concerns" over Mrs Zaghari-Ratcliffe.
She has been held in Tehran since April 2016 after being accused of spying, which she denies.
Her husband Richard Ratcliffe welcomed the news of the Foreign Secretary's visit to Tehran, saying that "him being there can only make things better".
He told Sky News: "Nazanin has a new court case on Sunday, so it is really, really great that he is able to be there, just to press how important it is that she could be home with her family."
He added: "I think him being there can only make things better. It makes a clear statement that he is concerned about Nazanin, he is concerned about the other cases.
"I am sure the fact that the Foreign Secretary is going will have given her some hope and fingers crossed that maybe something will come."
Her case gained worldwide attention when Foreign Secretary Boris Johnson mistakenly said she had been teaching journalism in the country, which the Iranian judiciary seized upon as proof she had not been on holiday.
He has since apologised for not being clearer with his choice of words.
