Iran and the U.S., holding talks in Rome, will have experts meet to discuss details of a possible deal over Tehran's rapidly advancing nuclear program, Iran's top diplomat says.

American and Iranian officials have begun their second round of indirect nuclear talks in Rome as the Trump administration weighs diplomacy against possible military action.

The United States and Iran are due to hold their second round of nuclear talks on Saturday, as what both sides are looking for in a deal begins to take shape.