A third round of face-to-face talks between Iran and the US, held with Pakistan as the mediator, has concluded in Islamabad, Iran's government said.
Following the end of the latest round, expert teams from both sides continued to exchange written texts as part of the negotiation process.
The talks ended at 3.12 am local time, according to Iranian media reports.
Sources said serious differences between the Iranian and US delegations remain unresolved, adding that progress depends on whether the US shifts from its "maximalist approach" toward a more realistic position, per Anadolu agency.
Another round of talks set for Sunday at Pakistan's request, with both Iran and the US agreeing to participate, according to the state-run IRIB network.
The third round of trilateral talks resumed on late Saturday in Islamabad after a dinner break, close to midnight, according to Pakistani government sources.
Earlier, the two sides held initial indirect talks before moving into face-to-face negotiations.
The US delegation is led by Vice President JD Vance, accompanied by special envoy Steve Witkoff and senior adviser Jared Kushner.
The Iranian delegation is headed by Parliament Speaker Mohammad Bagher Ghalibaf, with Foreign Minister Abbas Araghchi and senior security official Ali Bagheri Kani also taking part.
Iranian media said the negotiations entered a "sensitive phase," with expert teams engaged at the technical level through specialised committees.
Sources close to the Iranian delegation pointed to persistent differences between the two sides.
Pakistan is hosting the talks as part of efforts to end the broader regional conflict under a fragile two-week ceasefire brokered earlier this week.
