After less than a year on the job, the top counterterrorism adviser to President Donald Trump, Joe Kent, stepped down from his position in protest of the ongoing U.S.-Israel war with Iran.

Kent's announcement of his departure as head of the U.S. National Counterterrorism Center on Tuesday, March 17, marks the first resignation of a top Trump administration official over the war, which has stretched into its third week with no clear end in sight.

In a letter explaining his decision addressed to Trump and posted to social media, Kent said Iran did not pose a serious threat to the United States in advance of the Feb. 28 joint U.S.-Israel strikes that launched the war.

"I cannot in good conscience support the ongoing war in Iran," Kent said in the statement. "Iran posed no imminent threat to our nation, and it is clear that we started this war due to pressure from Israel and its powerful American lobby."

Trump responded Tuesday, March 17, saying he thought Kent was a "nice guy," but criticized his counterterrorism chief as "very weak on security."