The declaration comes after Christopher Wray made confusing remarks earlier this week that heightened tensions between the Republican presidential candidate and the law enforcement organization in the wake of the July 13 incident.
The former president barely survived the shooting at a Butler, Pennsylvania, campaign rally that claimed one life and seriously injured two more.
A Secret Service sniper shot and killed shooter Thomas Crooks, 20.
Many of Mr. Trump’s followers think that God intervened to save him, and the businessman has claimed that he had “God on his side.”
The Trump campaign was incensed after Mr. Wray’s testimony to Congress this week, which revealed that investigators were unsure if shrapnel or a bullet caused Mr. Trump’s injuries.
In a post on his Truth Social network, Mr. Trump further attacked Mr. Wray, claiming it was “no wonder the once storied FBI has lost the confidence of America”.
Former White House physician Ronny Jackson, a devoted supporter of Mr. Trump who has been attending to him since the assault, called it irresponsible to insinuate that anything other than a bullet caused his wounds.