The staunch Trump supporter has served as ambassador to Germany since 2018.
In a statement, Maguire thanked the president for the opportunity to serve in the temporary position.
“This has been the opportunity of a lifetime, and I am grateful for the tireless efforts and support of our intelligence professionals,” according to the statement. “I am committed to leading the IC until Ambassador Grenell assumes the role, and look forward to the next challenge.”
In his tweet, the president said Maguire may serve in another capacity within the administration.
The 53-year-old is a staunch Trump supporter who has served as ambassador in Berlin since May 8, 2018. He was confirmed by the U.S. Senate in a 56-42 vote on April 26, 2018.
Grenell will become the first openly gay member of the cabinet. The Michigan native is also a former spokesman at the United Nations and worked on the 2012 presidential campaign of Sen. Mitt Romney, R-Utah.
According to ABC News’ records, on Sept. 14, 2019, Grenell joined the president at the White House for dinner with Fred and Cindy Warmbier, whose son Otto died shortly after being released from captivity in North Korea in June 2017.
Grenell received a master’s degree in Public Administration from Harvard University and completed a bachelor degree at Evangel University in Springfield, Missouri, according to his biography posted on the State Department’s website.
ABC News’ Luc Bruggeman contributed to this report.