WASHINGTON ― Rob Greenway, a top adviser to President Donald Trump on the Middle East, is expected to step down Thursday as part of an exodus at the National Security Council following Wednesday’s storming of Capitol Hill by Trump supporters, an official with knowledge of the situation told Defense News.

The official, speaking on condition of anonymity, was not sure if Trump’s pledge of an “orderly transition” to President-elect Joe Biden on Jan. 20 was intended to head off further resignations, but said if so, “I don’t think anyone is listening anymore.”

In all, Greenway’s departure means at least six staffers at the National Security Council will have resigned since Wednesday. They include the senior director for Africa, Erin Walsh; the head of the NSC’s bureau tracking weapons of mass destruction, Anthony Ruggiero; the top Europe and Russia adviser, Ryan Tully, and Mark Vandroff, the NSC’s senior director for defense policy. Tully’s departure was first reported by Reuters.

The resignation of Trump’s deputy national security adviser Matt Pottinger Wednesday was first reported by Bloomberg.

The White House did not respond to a request for comment Thursday afternoon on any resignations in the wake of yesterday’s violent confrontation at the U.S. Capitol between a pro-Trump mob and Capitol and D.C. police.

David Larter contributed to this report.