- January: International Atomic Energy Agency (IAEA) confirms Iran is refining uranium to 20% fissile purity.
- February: UN inspectors end talks in Tehran without inspecting disputed military site at Parchin.
- April: Iranian President Mahmoud Ahmadinejad vows Iran will not surrender its nuclear rights.
- May: UN inspectors report they found find traces significantly upgraded uranium at an Iranian site.
- July: EU begins total ban on Iranian oil imports; US expands sanctions.
- September: IAEA demands access to Parchin; Iran calls EU sanctions "irresponsible."
- December: IAEA says it makes progress in talks with Iran. US imposes more sanctions.
- January: Iran says it will speed up nuclear fuel work.
- February: Iran's supreme leader Ayatollah Ali Khamenei rejects direct nuclear talks with the U.S. Iran and world powers meet, agree to more talks.
- May: IAEA says Iran has expanded nuclear activity.
- September: Iranian President Hassan Rouhani says Iran will not seek weapons of mass destruction. Iran and world powers agree to resume nuclear talks.
- October: Iran holds talks with five permanent members of U.N. Security Council and Germany.
- November: Iran holds two rounds of talks with world powers. Ayatollah Ali Khameni warns Iran will not retreat on its nuclear rights.