The United States has declared its 'final and best offer' to Iran following a 21-hour negotiation session in Islamabad, Pakistan, which ultimately ended without an agreement. Vice President JD Vance stated that the talks broke down primarily because Iran did not commit to abandoning its nuclear weapons ambitions. He emphasized the need for a long-term commitment from Iran to refrain from developing nuclear weapons, indicating that the US has not yet seen sufficient intent from Tehran. Although the details of the proposal were not disclosed, Vance mentioned that the US outlined clear red lines and areas of potential flexibility. The negotiations, which also touched on issues like frozen assets, were facilitated by Pakistan, which Vance credited for its mediation efforts. With no deal reached, the US has placed the responsibility on Iran to respond to its proposal, leaving the diplomatic future uncertain.