Trivelli was announced as the nominee of PresidentGeorge W. Bush to be the U.S. ambassador to Nicaragua on May 13, 2005. The nomination was sent to the Senate on May 16 and was confirmed on May 26.
Trivelli was the source of much controversy for his remarks about the 2006 Nicarguan presidential election and his warnings about U.S. economic retailiation if Sandinista candidate Daniel Ortega won the election. Specifically, he expressed the desire of the United States government to see the split conservative parties unite behind a single candidate, even going so far as to offer to fund such a joint primary election. Additionally, he explicitly threatened to cut off $175 million in Millennium Challenge Account funding.