Iranian Foreign Minister Mohammad Javad Zarif and his US counterpart John Kerry held the third round of their talks here on Sunday, IRNA reported.

The two diplomats are to focus on the ways to remove the points of difference still remaining in drafting the final nuclear document.

Kerry is to stay in Vienna to the last hour of the deadline set for compilation of the final draft.

His counterparts from Germany and the UK are expected to join him later.

The deadline for finalizing the nuclear deal between Iran and the 5+1 is set for June 30.