Complex sentence: The United States recognized Armenia on December 26,1991, and the embassy at Yerevan was opened on February 3,1992, with Steven Mann as Chargé d'Affaires "ad interim".
Split into simpler sentences: The United States recognized Armenia on December 26,1991. The embassy at Yerevan was opened February 3,1992, with Steven Mann as Chargé d'Affaires "ad interim".