Anyone going to the U.S. on official business for a government or designated international organization must obtain an A or G visa. A visas are required for anyone assigned to a foreign embassy or consulate in the U.S., as well as government officials on a temporary mission. G visas are required for individuals representing their government at or hired to work directly for certain international organizations located in the U.S.  G visas are also required for employees of such organizations stationed abroad who are required to travel to the U.S. temporarily for their work.