Iran official upbeat over nuclear talks, top delegate cautious

Iranian flag flies in front of the UN office building, housing IAEA headquarters, amid the coronavirus disease (COVID-19) pandemic, in Vienna, Austria, May 24, 2021. REUTERS/Lisi Niesner

DUBAi (Reuters) - Iranian government spokesman Ali Rabiei said on Tuesday he was optimistic over Tehran reaching an agreement soon at talks with world powers to revive a 2015 nuclear deal, although Iran's top negotiator cautioned that serious issues remained.

Iran and global powers have held several rounds ofnegotiations since April in Vienna, working on steps that Tehranand Washington must take on sanctions and nuclear activitiesto return to full compliance with the nuclear pact.