Richard L. Morningstar was named to the position on April 20, 2009. He led the United States delegation to the energy conference in Sofia on April 24 and 25, 2009.[6] On July 13, 2009, Morningstar represented the United States at the signing ceremony of the intergovernmental agreement of the Nabucco pipeline.[7][8] He has strongly opposed the possible participation of Iran in the Nabucco project.[9][10] Morningstar left office in March 2012 become the United States Ambassador to Azerbaijan, and the role has been left vacant since.