Mr Araghchi lauded the “relatively positive atmosphere”, high praise from a regime whose leaders sometimes chant “death to America”. Donald Trump was more effusive, saying his administration had “very good meetings” on Iran (although he said the same about tariffs, Russia and Ukraine). The two envoys’ next meeting was set for April 26th.

US President Donald Trump's renewed threat comes as Washington and Tehran continue talks over the Iran's nuclear program, with a third round slated for Saturday in Oman.