Iran said on Saturday that attempting to revive its landmark nuclear deal with world powers that was effectively scrapped by former US president Donald Trump was increasingly “useless”. “Today, the more we advance, the more the JCPOA becomes useless,” Foreign Minister Hossein Amirabdollahian said in a speech to students at the University of Tehran, using the initials of the official name of the nuclear deal. In 2015, Iran agreed to curbs on its nuclear programme in exchange for a lifting of sanctions. But while the deal was signed with several world powers – including China, Russia, Britain, F…