Washington, March 17 -- Joe Kent, director of the US National Counterterrorism Center, has resigned with immediate effect, becoming the most senior official to step down over the war with Iran, exposing an internal rift within President Donald Trump's administration.

In a resignation letter posted online, Kent said he could not support a conflict he believed lacked justification, arguing that Iran posed "no imminent threat" to Washington. He said he could not "in good conscience" back a war that risked American lives without clear benefit, warning against sending "the next generation off to fight and die".

Kent also suggested the conflict had been driven by external pressure rather than direct national security needs, cautioning that the ...