Iran already has a nuclear deal, made in 2015, between Iran and six major powers: Germany, the UK, France, Russia, China and the US. I assume this question is asking will there still be a deal if President Donald Trump withdraws his support, as he has been consistently threatening to do.
Trump has three main complaints about the deal: it does not include Iran’s ballistic missile program, there is no permission for international inspectors to visit Iranian nuclear sites, and “sunset clauses” only limit Iranian nuclear activity for 10 years. The next date for Trump to approve or reject the deal is sometime in early to mid-May 2018. Who knows what Trump will do? His behavior is impossible to predict.