Iran and the United States are set to begin a fifth round of high-stakes nuclear talks in Rome on Friday amid growing skepticism in Tehran about the chances of a deal as Washington hardens its position.

DUBAI, United Arab Emirates (AP) — Iran’s top diplomat warned Thursday that his country would take “special measures in defense of our nuclear facilities” if Israel continues to threaten Tehran’s atomic sites, raising the stakes further ahead of a new round of talks with the United States.