Trump wrote in his letter to bureau’s head that he took such decision as Comey was not able to lead the department effectively.
"It is essential that we find new leadership for the FBI that restores public trust and confidence in its vital law enforcement mission," the message reads.
Trump told Comey in the letter that he accepted the recommendation of Attorney General Jeff Sessions that he could no longer provide effective leadership.
At the same time, US president thanked Comey for the work done.
Sessions recommended to remove Director James B. Comey, Jr. and identify "an experienced and qualified individual to lead the great men and women of the FBI".
"It is essential that this Department of Justice clearly reaffirm its commitment to longstanding principles that ensure the integrity and fairness of federal investigations and prosecutions. The director of the FBI must be someone who follows faithfully the rules and principles of the Department of Justice and who sets the right examples for our law enforcement officials and others in the department," Sessions said.