Talks with Iran over releasing British-Iranian Nazanin Zaghari-Ratcliffe are "going right up to the wire", Boris Johnson has said.
But the Prime Minister added he could not say more as "negotiations (with Iran) continue to be under way".
Asked by broadcasters at the Emirates Palace hotel in Abu Dhabi whether a UK negotiating team was currently in Iran capital Tehran, the Prime Minister said: "It is true and it has been for a long time that we're negotiating for the release of our dual nationals in Tehran.
