Perez de Cuellar, Javier, PEH rehs deh KWAY yahr, hah vee AIR, (1920-...), is a diplomat from Peru who served as secretary-general of the United Nations (UN) from 1982 to 1991. He was the UN's fifth secretary-general and its first from Latin America. Perez de Cuellar worked to improve the UN's administrative efficiency. He also took part in negotiations on conflicts in Afghanistan, Central America, Cyprus, the Falkland Islands, and the Persian Gulf. In 1988, he helped negotiate a truce between Iran and Iraq. In 1991, he led talks that resulted in a treaty ending a civil war in El Salvador.