I don't think those ruling Iran believe it can be great without nuclear weapons
Trump appears to be having some success with this kind of outreach to North Korea, but I doubt it will work with the Islamic religious bigots who rule Iran. These bigots seem to believe that Shia Islam should dominate the world and are willing to commit mass murder to achieve that objective. They really have little empathy for their own people who suffer while they try to achieve this objective. They went along with Obama's deal because it enriched them and appeared to be no long term obstacle to their objectives of having nuclear weapons.
‘Let’s make Iran great again’: Trump reaches out to Tehran, still threatens more sanctions
Iran has shown no interest in renegotiating a new agreement with a Trump administration that has worked to strangle its economy and prevent it from selling oil on the international market.