Iran and the United States held a fourth round of negotiations on Sunday over Tehran’s rapidly advancing nuclear programme, just ahead of a visit by US President Donald Trump to the Middle East this week.

The talks ran for some three hours in Muscat, the capital of Oman, which has been mediating the negotiations, said a US official. Iranian state television quoted Iranian Foreign Ministry spokesperson Esmail Baghaei as also saying the talks took place for that long and that a decision on the next round of talks is under discussion.

Baghaei did not elaborate. The US official, speaking on condition of anonymity to discuss the closed-door negotiations, offered a little bit more, describing them as being both indirect and direct.

“Agreement was reached to move forward with the talks to continue working through technical elements,” the US official said. “We are encouraged by today’s outcome and look forward to our next meeting, which will happen in the near future.”

The talks seek to limit Iran’s nuclear programme in exchange for the lifting of some of the crushing economic sanctions the US has imposed on the Islamic Republic. (AP)