Ricky Waddell, President Donald Trump's deputy national security advisor, is the latest official leaving the Trump administration, a White House spokesperson said Thursday.
"Rick will be leaving and his departure date has yet to be confirmed," the official told reporters.
New national security advisor John Bolton is seeking to replace Waddell — who was hand-picked by Bolton's predecessor, Gen. H.R. McMaster — with his own appointee, according to Axios, which first reported Waddell's departure.
Waddell is the latest in a growing wave of departures from national security agencies as Bolton becomes a top aide to Trump.
On Wednesday, the White House confirmed that Nadia Schadlow, a strategy advisor who worked under McMaster, is resigning and will leave her position at the end of the month.
The day before, Trump administration officials said that homeland security advisor Tom Bossert would be stepping down. "The President is grateful for Tom's commitment to the safety and security of our great country," White House press secretary Sarah Huckabee Sanders said in a statement.
And on Sunday, a spokesman for the national security council, Michael Anton, announced that he will be leaving the White House.
The White House did not immediately provide additional comment.
The high-level turnover in U.S. security agencies is playing out at a perilous time for U.S. relations with allies and adversaries around the world.
As the Trump administration mixes its messages on a military response to Syria's alleged use of chemical weapons on a rebel town this weekend, Trump has also found a sudden willingness to criticize Russia for its possible role in the deadly attack.
Russia's relations with the West were already strained after numerous world leaders blamed the Kremlin for an alleged nerve agent attack on an ex-spy and his daughter living in England. The U.S. expelled 60 Russian diplomats in response to the alleged poisoning.
Meanwhile, the White House says it is still preparing for an unprecedented face-to-face meeting with North Korean leader Kim Jong Un. But the chance of such a meeting happening could be complicated by the appointment of Bolton, who wrote an op-ed in The Wall Street Journal in February laying out a case for a first strike on North Korea.
Bolton is seen as much more hawkish than McMaster, who received bipartisan praise when he joined the administration. Now Bolton, a more controversial pick, is clearing his ranks of McMaster's influence.
The changes are taking place as the Trump administration operates without a top diplomat. Rex Tillerson, the former CEO of Exxon Mobil, was fired by Trump in March. His successor, CIA Director Mike Pompeo, has not yet been confirmed by Congress. He testified to the Senate Foreign Relations Committee on Thursday.
Correction: An earlier version gave the wrong location for the home of a former Russian spy who was attacked with a nerve agent in England. It also incorrectly described the role of national security advisor. The advisor is a top aide to the president but is not a Cabinet member.