The remaining parties to the 2015 Joint Comprehensive Plan of Action, which was aimed at halting Iran’s nuclear activities in return for global sanction relief, met on Tuesday in Vienna for what both sides called “constructive” talks. British, Chinese, French, German and Russian officials who met with Iran’s representatives hope to bring Tehran back into compliance with the largely aborted deal, while the Islamic Republic has demanded that new sanctions, re-imposed by former President Donald Trump after he quit the pact in 2018, be lifted first. European mediators on Tuesday shuttled between Iran’s negotiators and the United States envoy for Iran, Robert Malley, also present in the Austrian capital, as Tehran has so far refused a direct face-to-face with Washington officials. While both sides tempered expectations in the days leading up to the Vienna summit, State Department spokesman Ned Price noted Tuesday’s indirect back and forth was a “welcome … constructive … potentially useful step.”