Peace talks between the United States and Iran stalled after disagreements over Tehran’s nuclear commitments, with the scope and duration of uranium enrichment curbs emerging as the key sticking point.According to reports by the Wall Street Journal and the New York Times, Washington proposed a 20-year freeze on Iran’s uranium enrichment in its proposal. However, Tehran said it could only agree to a five year sanction.Tehran has proposed suspending uranium enrichment for up to five years — an offer the Trump administration rejected, insisting on 20 years, two senior Iranian officials and one US official told the New York Times.This comes after US President Donald Trump’s repeated assertion that Tehran permanently end domestic enrichment amid concerns it could provide a pathway to nuclear weapons capability.Apart from disagreements over Hormuz and sanctions, the two sides also differed on the scope of a potential deal. While Washington prioritised the nuclear issue and Hormuz, Tehran sought a broader agreement, news agency Reuters reported, quoting two sources.During one tense moment, raised voices were heard outside the negotiating room before Pakistan’s Army Chief Asim Munir and foreign minister Ishaq Dar called for a tea break and moved the delegations back into separate rooms, a government source told Reuters.“There was a ⁠strong hope in the middle of the talks that there would be a breakthrough and the two sides would reach an agreement. However, things changed within no time,” a Pakistani government source told Reuters.Another source involved in the talks said the sides came “very close” to an agreement and were “80% there” before hitting issues that could not be resolved on the spot.Two senior Iranian sources described the atmosphere as heavy and unfriendly, adding that while Pakistan tried to soften the mood, neither side showed any willingness to ease tensions.Meanwhile, officials told The Wall Street Journal they were considering a second round of face-to-face talks, though no details were disclosed.Beyond uranium enrichment, other key issues included reopening the Strait of Hormuz — a critical global energy transit route effectively blocked by Iran – and the lifting of international sanctions on Tehran, Reuters reported, citing sources.According to the agency, negotiations at Islamabad’s Serena Hotel were conducted across two separate wings and a shared area: one for the US delegation, one for the Iranians, and a common space for trilateral meetings involving Pakistani mediators.Mobile phones were reportedly barred from the main room, forcing delegates – including US Vice President JD Vance and Iranian Parliamentary Speaker Mohammad Baqer Qalibaf – to step outside during breaks to communicate with their respective governments.“There was a strong hope in the middle of the talks that there would be a breakthrough and the two sides would reach an agreement. However, things changed within no time,” a Pakistani government source said.The talks stretched for more than 20 hours. When discussions turned to guarantees – including non-aggression commitments and sanctions relief — the tone of Iranian foreign minister Abbas Araghchi reportedly sharpened, two Iranian sources told Reuters.