United Nations Security Council Resolution 457, adopted unanimously on 4 December 1979, addressed the ongoing Iran hostage crisis. After expressing concern at the level of tensions between Iran and the United States as a potential threat to international security, the Council called on Iran to immediately release hostages held at the American embassy in Tehran and allow them to leave the country. The resolution reminded all Member States to respect the Vienna Convention on Diplomatic Relations and Vienna Convention on Consular Relations, which urged countries to respect the inviolability of diplomatic personnel and the premises of their diplomatic missions.