By Parisa Hafezi and John Irish DUBAI (Reuters) -Iranian and U.S. negotiators wrapped up a fifth round of talks on Friday, with mediator Oman saying there was some limited progress in negotiations aimed at resolving a decades-long dispute over Tehran's nuclear ambitions.

Depending on who you ask, a nuclear agreement between Iran and the United states is either a non-starter or almost a done deal.

Iran and the United States are set to resume nuclear talks in Rome amid rising tensions, hard-line demands, and Israeli threats of military action. With uranium enrichment at the core of the standoff,

Iran’s top diplomat has warned that his country would take “special measures” to defend its nuclear facilities if Israel continues to threaten them, raising the stakes further ahead of a new round of talks with the United States.