By Parisa Hafezi and John Irish DUBAI (Reuters) -Iranian and U.S. delegations wrapped up a fifth round of talks in Rome on Friday and signs of some limited progress emerged in the negotiations aimed at resolving a decades-long dispute over Tehran's nuclear ambitions.

Trump in his first term in 2018 ditched a 2015 nuclear pact between major powers and Iran. Since returning to office this year, he has restored a "maximum pressure" campaign on Tehran and reimposed sweeping US sanctions that continue to hobble the Iranian economy.