Diplomats from Iran and world powers have reconvened in Vienna, seeking to revive the 2015 nuclear deal. The negotiations, attended by Britain, China, France, Germany, Iran, Russia and indirectly the United States, were halted at the end of last month. 

Former President Donald Trump withdrew the U.S. from the deal in 2018 and reimposed economic sanctions on Iran, prompting Tehran to pull back from its commitments under the deal and step up its nuclear activities. Iran insists that its nuclear program is peaceful, but western parties said it will render the accord an "empty shell." 

China's envoy to the UN voiced support for Iran's continued efforts to resolve the nuclear issue through negotiations. The parties have been negotiating in Vienna since last year, and officials said talks are in their final stages.