The Haitian government hired Roger J. Stone Jr., a confidant of President Trump, to lobby the Trump administration on Haiti’s behalf. The contract is worth nearly $800,000, according to a document filed with the Justice Department. Mr. Stone was hired by Haiti’s Foreign Ministry to conduct unspecified “issue advocacy” on U.S. government policy relevant to Haiti. Haiti’s prime minister, Alix Didier Fils-Aimé, declined to discuss details but highlighted migration as a priority.

Mr. Stone, 74, confirmed the contract but declined to discuss the nature of his work. He is a close friend of Mr. Trump, though not well known for work related to Latin America. In May, he posted on social media about Haiti’s elections, stating, “There cannot be elections until there is security and stability.” Haiti has not held elections in 10 years, and violence fueled by gangs has set off a humanitarian crisis.

Haiti already pays $35,000 a month for lobbying services to Continental Strategy, run by Carlos Trujillo, a former Trump ambassador. Mr. Stone could work on the Trump administration's decision not to extend protected status for Haitians, affecting an estimated 300,000 Haitians facing deportation. The end of the protection has led to a spike in detentions and deportations to Haiti, a major challenge for the poor country.

It is unclear why Haiti hired Mr. Stone, who has built a reputation for using his connections to Mr. Trump to win pardons. Last year, he was a key intermediary in Mr. Trump’s pardon of a former Honduran president, Juan Orlando Hernández, convicted of drug trafficking.