There are still disagreements between Iran and the world powers in talks to revive the 2015 nuclear deal, US national security adviser Jake Sullivan said on Sunday, repeating that the ultimate decision on the issue lies with the Supreme Leader. "There is still a fair distance to travel on some of the key issues, including on sanctions and on the nuclear commitments that Iran has to make," Sullivan said in an interview with broadcaster ABC News. Sullivan wouldnt detail any discussions around lifting specific sanctions, including those placed on Irans new president-elect, Ebrahim Raisi, under the Trump administration for human rights abuses, as the US and Iran continue to negotiate reviving the nuclear deal. "The question of which sanctions will be lifted is currently being negotiated in Vienna and Im not going to conduct those negotiations in public," he said. "I think what we need to do in the United States is keep our eye on the ball," Sullivan told ABC "This Week" anchor George Stephanopoulos. "Our paramount priority right now is to prevent Iran from getting a nuclear weapon. We believe that diplomacy is the best way to achieve that, rather than military conflict." "Were going to negotiate in a clear-eyed, firm way with the Iranians to see if we can arrive at an outcome that puts their nuclear program in a box," he continued.