Another member of the White House's National Security Council resigned Thursday, as newly-installed national security adviser Ambassador John Bolton cleans house during his first week in the administration.

Deputy national security adviser Ricky Waddell resigned from his post Thursday, the White House said.

“Rick will be leaving and his departure date has yet to be confirmed,” a White House official said in a statement.

Waddell, an Army reserve major general, joined the NSC in May 2017, following President Trump’s first deputy national security advisor K.T. McFarland’s exit.

Waddell reported directly to H.R. McMaster, who resigned as national security adviser last month.

DEPUTY NATIONAL SECURITY ADVISER NADIA SCHADLOW RESIGNS ON BOLTON'S THIRD DAY AT WHITE HOUSE

Waddell’s resignation follows a slew of other departures this week: NSC spokesman Michael Anton resigned Sunday, White House homeland security adviser Thomas Bossert resigned Monday, and deputy national security adviser Nadia Schadlow resigned Tuesday.

Bolton, who was appointed last month and had his first day at the White House Monday, is said to be “cleaning house” at the NSC, according to a White House source.

A national security source also told Fox News that Bolton is considering a merger of the NSC and Homeland Security Council (HSC) within the White House. Currently, the NSC and HSC staff function as separate bodies, with their own meetings and policy issues, but share a staff.

HOMELAND SECURITY ADVISER TOM BOSSERT RESIGNS, WHITE HOUSE SAYS

Under the George W. Bush administration, the HSC and NSC worked as separate staffs. During the early years of the Obama administration, HSC and NSC merged, but later split.

The NSC primarily focuses on U.S. foreign policy and nuclear proliferation, while the HSC focuses on national defense-related issues like terrorism and border security.

If Bolton does merge the HSC and NSC, the bodies would hold joint meetings on mutually-agreed upon issues, and provide joint policy recommendations to the president, a national security source told Fox News.

JOHN BOLTON TO REPLACE H.R. MCMASTER AS WHITE HOUSE NATIONAL SECURITY ADVISER, TRUMP SAYS

Bolton has previously served in the administrations of presidents Ronald Reagan, George H.W. Bush, and George W. Bush, and served as a Bush lawyer during the 2000 Florida recount. Bolton served as a U.S. permanent representative to the United Nations from 2005 to 2006, and as undersecretary of state for arms control and international security from 2001 to 2005.

The position of White House national security adviser does not require Senate confirmation. Bolton has been a controversial pick for Trump, who has drawn criticism from Democrats since his appointment.

Bolton is now Trump’s third national security adviser—replacing McMaster, who replaced Michael Flynn.

Fox News’ Jennifer Bowman, John Roberts and Gillian Turner contributed to this report.