Retired Navy SEAL Adm. William McRaven stepped down from a defense advisory role just four days after issuing a stirring rebuke against President Trump.

McRaven's criticism was a response to the president's threats against former CIA director John Brennan.

Trump has threatened to revoke security clearances of several former national security officials, an act McRaven labeled as a "McCarthy-era" tactic.

The Navy SEAL admiral who challenged President Donald Trump to revoke his security clearance in the Washington Post has stepped down from the Defense Innovation Board, Defense News reported.

Admiral William McRaven's resignation from the Pentagon's leading technology advisory board came on the heels of his controversial and viral Washington Post op-ed, which he penned after Trump threatened to revoke the security clearance of former CIA director John Brennan.

The Defense Innovation Board, launched in 2016, brings together leading experts in science and technology, and allows thinkers such as Neil Degrasse Tyson to provide "creative solutions" to the Department of Defense. The panel also includes figures like former Google Executive Chairman Eric Schmidt and the noted biographer Walter Isaacson.

McRaven said he would consider it an honor to see his own clearance revoked, so he could join the growing list of those critical of the president's "McCarthy-era tactics."

The former SEAL, who oversaw the 2011 raid that killed Osama bin Laden, sharply criticized Trump's leadership, saying the president has "humiliated us on the world stage and, worst of all, divided us as a nation."

According to a Defense News report, McRaven resigned from the board just four days after the publication of his presidential rebuke.

Is is unclear whether McRaven's clearance has been revoked, as reportedly happened to Brennan, and the former SEAL promised Trump that regardless "the criticism will continue until you become the leader we prayed you would be."