United Nations Security Council Resolution 1664 was adopted unanimously on March 29, 2006; after recalling resolutions 1595 (2005), 1636 (2005) and 1644 (2005), the Council requested the Secretary-General Kofi Annan to consult with the Lebanese government concerning the establishment of an international tribunal to try those responsible for the assassination of Prime Minister Rafic Hariri and 22 others in February 2005.