In 2015, Iran reached a deal with the US, Russia, China, the UK, France and Germany, and agreed to curb its nuclear programme in exchange for the lifting of international sanctions. However, in 2018, Donald Trump, a year into his first term as US president, pulled out of the pact.

Last week, Trump said he had sent a letter to Iranian Supreme leader Ayatollah Ali Khamenei proposing nuclear talks, adding that “there are two ways Iran can be handled: militarily, or you make a deal”.

Iranian President Masoud Pezeshkian responded that he would not negotiate with the US while being “threatened”, and Iran would not bow to US “orders” to talk.

Iran was further enraged after six of the United Nations Security Council’s 15 members – the US, France, Greece, Panama, South Korea and the UK – held a closed-door meeting this week to discuss its nuclear programme. Tehran said the meeting was a “misuse” of the UN Security Council.

In the run-up to the Beijing talks on Friday – attended by the vice foreign ministers of China, Russia and Iran – China said it hoped the trilateral meeting would help create “conditions” for the early resumption of dialogue and negotiations.

Iran has long denied that it is working on developing a nuclear weapon. However, the International Atomic Energy Agency warned last month that Tehran was “dramatically” accelerating enrichment of uranium to near the roughly 90% weapons-grade level.