Over the years, Martini has served Guatemala in a number of diplomatic roles, first representing his nation’s military dictatorship and later its civilian government. During the early 1980s, he served as ambassador to Venezuela. Later in the decade he was vice foreign minister. He was Guatemala’s ambassador to the United Nations in New York, circa 1993 to 1998. In that role, he chaired Guatemala’s delegations to the Cairo Population Conference of 1994 and the Fourth World Conference on Women in Beijing in 1995. He also served as chairman of the Committee of the United Nations Population Award in 1996-1997. In 1996 and 1997, he was involved in negotiations that led to a Security Council resolution, initially vetoed by China because of Guatemala’s relations with Taiwan, which allowed a UN peacekeeping force to monitor the cease-fire agreement signed on December 4, 1996, by the Guatemalan government and the Unidad Revolucionaria Nacional Guatemalteca (URNG).

 

In 1998, he was posted as ambassador to Belgium, with concurrent representation to Luxembourg. He also served as Guatemala’s ambassador to the European Union until 2000. From circa 2002 to 2004, he served as Guatemala’s Ambassador to Trinidad and Tobago. Back in Guatemala by the end of the decade, he was Director-General of International, Multilateral and Economic Relations at the Ministry of Foreign Affairs.