US and Iranian delegations will gather in Rome Saturday for a second round of high-level talks on Tehran’s nuclear program amid tempered optimism about a diplomatic way forward.

Iran and the United States will hold a new round of nuclear talks in Rome on Saturday to resolve their decades-long standoff over Tehran's atomic aims, under the shadow of President Donald Trump's threat to unleash military action if diplomacy fails.

As far as biographies go, the two men in charge of the delicate negotiations between Iran and the United States over Tehran’s rapidly advancing nuclear program couldn’t be more different.