Dhaka, April 20 -- 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.Iran's Foreign Minister Abbas Araqchi and Trump's Middle East envoy Steve Witkoff will negotiate indirectly through mediators from Oman, a week after a first round in Muscat that both sides described as constructive.Araqchi has arrived in Rome to attend the second round of the talks, according to a post on his Telegram account. He said in Moscow on Friday that Iran believes reaching an agreement on its nuclear programme with the United States is possible as long as Washington ...