Iran and the United States begin high-stakes talks to reach a new nuclear deal on Saturday foreshadowed by President Trump’s threat of military strikes as a consequence of failure and Tehran’s warning any attack on it would drag the US into another Middle Eastern conflict.

Iran says its nuclear programme is for civilian purposes only. It insists it is not trying to develop nuclear weapons, but many countries - as well as the global nuclear watchdog, the International Atomic Energy Agency (IAEA) - are not convinced.