Direct talks between the US and Iran in Pakistan ended in a deadlock after 21 hours as the parties failed to reach an agreement on nuclear enrichment.JD Vance and Mohammad Bagher Ghalibaf led negotiations at the Serena Hotel in Islamabad while a fragile six-week ceasefire remains in effect.Shehbaz Sharif facilitated the meeting as regional tensions persist following Israeli strikes in Lebanon and Saudi security concerns.