ROME—U.S. and Iranian officials are set to begin a fifth round of nuclear negotiations Friday, with Tehran warning that talks could collapse if the two sides can’t overcome a pivotal clash over the shape of a deal.

Iran said it’s “time to decide” ahead of Friday’s nuclear talks with the U.S., with the main sticking point being whether Tehran will be able to continue

Iran's Abbas Araghchi said Thursday the US would "bear legal responsibility" for an Israeli attack on its nuclear facilities, while the Trump administration expressed confidence entering the fifth round of talks with Iran over a nuclear deal.