President-elect Donald Trump jettisoned a respected national security expert from his transition team on Tuesday in a sign that he may be settling on loyalists such as former New York City Mayor Rudy Giuliani and conservative ideologues such as former U.N. Ambassador John Bolton to staff his administration.

Mike Rogers, a former U.S. congressman from Michigan who headed the House of Representatives intelligence committee, said he was leaving the transition team. His sudden departure was announced four days after New Jersey Governor Chris Christie was abruptly replaced as the head of Trump’s transition team by Vice President-elect Mike Pence.

Giuliani and Bolton are being considered for secretary of state, according to sources close to Trump. Giuliani, New York’s mayor at the time of the Sept. 11, 2001, attacks by Islamist al Qaeda militants, is known as a hard-liner on national security matters. Bolton is also a foreign policy hawk who said last year the United States should bomb Iran to halt its nuclear program.

With fewer than 70 days until his Jan. 20 inauguration, the Republican president-elect has little time to settle on Cabinet members and other senior appointees. Trump, who had never previously run for office until his surprise victory over Democrat Hillary Clinton last week, will eventually need to fill roughly 4,000 open positions.

Pence has not yet filled out paperwork required by law to work on the transition with Democratic President Barack Obama’s outgoing administration, the White House said.

Two national security officials said Trump’s operation had been slow to get up to speed and had not yet deeply engaged with security and intelligence agency personnel who were ready to start helping them out.

A former Republican government official said Rogers’ exit from the transition team was part of a purge of relatively moderate individuals who had worked on the transition with Christie before Pence took over.

“Everybody who is associated with Chris Christie is being purged. End of story,” said the former official, who spoke on condition of anonymity.

Pence and other top advisers, including Alabama Senator Jeff Sessions and Wall Street executive Steve Mnuchin, did not speak to reporters as they arrived at Trump’s New York City apartment building on Tuesday.

Mnuchin is a leading candidate to serve as treasury secretary, according to sources close to Trump. Sessions, one of Trump’s closest allies in Washington, might serve as secretary of defense.

Some prominent Republican experts who might be tapped to fill out a Trump administration, meanwhile, were warning colleagues to steer clear.

“After exchange w Trump transition team, changed my recommendation: stay away. They’re angry, arrogant, screaming ‘you LOST!’ Will be ugly,” former State Department official Eliot Cohen wrote on Twitter.

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Trump has filled two positions so far. His choice of Republican Party insider Reince Priebus to be White House chief of staff was heralded by Republican leaders as an indication he wants to work with the party in Congress. Republicans maintained their majority in both the Senate and House in last week’s election, but a number of Republicans in Congress had opposed Trump’s candidacy.

However, Trump’s appointment of Steve Bannon as chief strategist was roundly criticized by Democrats, civil rights organizations and some Republicans. They denounced the former Breitbart News chief as having made the website a forum for the “alt-right,” a loose grouping of neo-Nazis, white supremacists and anti-Semites.

Neither Priebus nor Bannon need Senate confirmation for their posts, but Cabinet posts do, and some of Trump’s possible picks could face a difficult time winning approval.

Republican Senator Rand Paul criticized Bolton on Tuesday for the former U.N. ambassador’s support of the Iraq war. Trump regularly attacked Clinton during the campaign for her support for the war while she was a U.S. senator.

Trump loyalist Ben Carson, who advised Trump after dropping his own presidential bid earlier this year, has opted against accepting a Cabinet position in his administration, his spokesman said.

Carson, a retired neurosurgeon with no government experience, had been mentioned as a possible head of the Education Department or the Health and Human Services Department.

“His life has not prepared him to be a Cabinet secretary,” said Armstrong Williams, Carson’s business manager.