Former national security adviser John Bolton argued forcefully against easing sanctions on Iran directly before President Trump unceremoniously fired him on Twitter on Tuesday. The president reportedly discussed the potential strategy at an Oval Office meeting on Monday as a means to restarting negotiations with Iran. According to people familiar with the interaction, Bolton, well-known for his aggressive approach toward Iran, voiced his disagreement. His departure was announced the next day. Bolton has since contradicted the president’s account of his leaving the White House, claiming instead that he chose to resign.

Trump is reportedly hoping to sit down with the president of Iran, Hassan Rouhani, later this month in New York City during the annual United Nations General Assembly. Formal talks between the two leaders would be unprecedented in the history of United States foreign policy, and are unlikely if American sanctions remain as is. Bolton’s departure, however, could improve the likelihood of such a meeting.