World Powers, Iran Hold 'Constructive' Talks Iran and world powers held what they described as “constructive” talks on Tuesday and agreed to form working groups to discuss the sanctions Washington might lift and the nuclear curbs Tehran might observe as they try to revive the 2015 nuclear deal. European intermediaries have started shuttling between Iranian and US officials in Vienna as they seek to bring both countries back into compliance with the accord, which lifted sanctions on Iran in return for curbs to its nuclear programme. Former US President Donald Trump withdrew from the deal in 2018, prompting Iran to steadily overstep the accord’s limits on its nuclear program designed to make it harder to develop an atomic bomb - an ambition Tehran denies.