Iran and the United States are preparing for a fifth round of negotiations over Tehran’s rapidly advancing nuclear program, with enrichment emerging as the key issue

DUBAI (Reuters) -Iranian and U.S. negotiators will resume talks on Friday in Rome to resolve a decades-long dispute over Tehran's nuclear ambitions, despite Iran's supreme leader warning that clinching a new deal might be insurmountable amid clashing red lines.

A round of U.S-Iran talks has been announced to take place in Italy as tensions loom over negotiations for a new nuclear agreement. Newsweek has contacted the U.S. State Department and the Iranian Foreign Ministry for comment.