Iran should not talk to the US about anything and instead do its plan on its own. There is no legal or logical reason why Iran should not have nuclear power, healthcare, and weaponry when compared to the US.
Why try to reach an agreement with someone who is just going to rip it up and throw it in your face in a few years? Backstabbing and broken promises are a byproduct of empires and the US has a long trail of those behind it.
They see from Russia how effective it is to pretend to work with Trump as a means of stalling any US actions.
go back far enough and all governments have a long trail of anything bad.
Trump has a lifetime of broken agreements.
There are no guarentees anymore. The age of diplomacy and the rules based order is over. This is the age of action and consequence.