TEHRAN - Iran and the United States have "reached a conclusion on a major part of the issues under discussion," but the signing of an agreement is not imminent, Iran's Foreign Ministry spokesperson Esmaeil Baghaei said on Monday.

Iran says intense diplomatic activity in Tehran could mark a decisive stage in efforts to reach a peace agreement with the United States.

Iran says negotiations with the US are far from a breakthrough, with major gaps still separating the two sides.