TEHRAN, Iran (AP) — Iran’s president has offered his most optimistic assessment yet of ongoing talks to resuscitate his country’s nuclear deal with world powers. President Hassan Rouhani on Thursday claimed there had been “major” agreement among diplomats involving sanctions and other issues. However, other nations involved suggested challenges remain. Mikhail Ulyanov, a Russian diplomat involved in the talks, tweeted that it “is obvious now that the Vienna talks on (the deal) will not be completed by May 21 as the participants hoped.” Others offered similar comments. Rouhani’s remarks come as Iran prepares for a June 18 election to determine who will replace him. Saving the deal could boost reformist and moderate candidates backing Rouhani’s agenda.