Raisi appears to defend Vienna negotiations while country's top diplomat and a security official points finger at US for deadlock, saying Washington making unreasonable proposals

Ali Bagheri Kani arrives in Austrian capital following sudden trip back to Tehran, with EU envoy indicating new agreement awaiting Islamic Republic's okay

Former US vice president and rumored 2024 contender says he believes Republicans will retake control of the White House and 'end the JCPOA' if it is revived

Tehran's top negotiator heads back for consultations amid Russian complications, but is slated to return to Vienna on Wednesday

White House dismisses possibility Russia sanctions will hinder talks in Vienna, saying both Washington and Moscow share common goal of preventing Tehran from obtaining nukes

But secretary of state says initiative must ensure Ukraine's sovereignty, updates foreign minister on status of Iran talks in Vienna as Israel-opposed deal approaches

Following Moscow's insistence that sanctions over Ukraine not harm its cooperation with Islamic Republic, Tehran says it won't allow 'external factor to affect national interests'

Supreme National Security Council says negotiators in Vienna will seek 'creative ways' to proceed as Moscow links efforts to save 2015 pact to US sanctions over Ukraine invasion

US secretary of state dismisses Moscow's stipulation that new measures it faces over Ukraine invasion won't impact its rights in talks to revive 2015 nuclear pact

Outstanding questions remain over past presence of nuclear material at undeclared sites; Grossi says after meetings with Iranians that there's 'no predefined outcome' to agreement