President-elect Donald Trump, who clashed with leading Republicans throughout his campaign, faced growing tumult in his national security transition team on Monday as key members of his own party appeared to question his views and personnel choices.Former congressman Mike Rogers (R-Mich.), a former FBI agent who is a widely respected voice on national security, announced that he is leaving his position as a senior national security adviser to Trump’s transition team. His departure came as Eliot Cohen, a leading voice of opposition to Trump among former GOP national security officials during the campaign, blasted Trump’s transition team in a tweet.

Perhaps the most influential Republican on national security matters, Sen. John McCain (R-Ariz.), weighed in on Trump’s efforts to work with Russian President Vladi­mir Putin, saying any efforts to “reset” relations with Russia are unacceptable.

McCain, the Senate Armed Services Committee chairman who had a difficult relationship with Trump during the campaign, issued a statement blasting Putin as “a former KGB agent who has plunged his country into tyranny, murdered his political opponents, invaded his neighbors, threatened America’s allies and attempted to undermine America’s elections.’’

The confusion came as Trump met Tuesday with incoming Vice President Mike Pence to discuss Cabinet and top White House personnel choices. Pence last week replaced New Jersey Gov. Chris Christie (R) as head of Trump’s overall transition efforts, and Christie’s associates — who had been Trump’s link to the GOP mainstream for months — now find themselves losing influence.

A number of Christie allies have been told they were no longer in line for top posts, according to several people familiar with the transition, who spoke on condition of anonymity to speak candidly.

Now operating below Pence, the people said, are advisers who are close to Sen. Jeff Sessions (R-Ala.) — himself a top Trump associate known for his hardline views on immigration — and former Breitbart News head Stephen K. Bannon. Bannon’s recent appointment as chief White House strategist was denounced by advocacy groups and Democrats, who accuse him of racist, anti-Semitic and misogynist views.

Inside Trump Tower in Manhattan, where the president-elect is planning his government, the shift is seen as a clear signal that Trump will govern more in line with the populist, hardline campaign he ran, the people said.

In another surprising development on Tuesday, retired neurosurgeon Ben Carson, who has been a confidant to Trump since the end of the Republican primaries, is unlikely to join the administration but will remain an informal adviser.

“The way I’m leaning is to work from the outside and not from the inside,” Carson said in an interview. “I want to have the freedom to work on many issues and not be pigeonholed into one particular area.”

Carson, who is Trump’s most high-profile African American supporter, has been under consideration for several positions in Trump’s Cabinet, including secretary of health and human services.

Adding to the uncertainty, former New York City mayor Rudy Giuliani appeared to take himself out of the running for attorney general. Giuliani, a former U.S. attorney and a top Trump adviser, had been considered a leading candidate for the prestigious post.

“I won’t be attorney general,” Giuliani said Monday at a Wall Street Journal event.

Rogers could not be reached for comment on his departure from Trump’s team. But Bloomberg Politics, citing people familiar with the matter, said Rogers was asked to leave by senior transition team members.

Cohen, meanwhile, drew widespread attention for his tweet.

“After exchange w Trump transition team, changed my recommendation: stay away. They’re angry, arrogant, screaming “you LOST!” Will be ugly,’’ tweeted Cohen, who served from 2007 to 2009 as counselor to then-Secretary of State Condoleezza Rice. He was a driving force behind an open letter last spring — eventually signed by 122 Republican national security leaders — who opposed Trump’s candidacy.

Cohen, who last week had urged career officials to serve in Trump’s administration, said in an interview that a longtime friend and senior transition team official had asked him to submit names of possible national security appointees. After he suggested several people, Cohen said, his friend emailed him back in terms he described as “very weird, very disturbing.”

“It was accusations that ‘you guys are trying to insinuate yourselves into the administration…all of YOU LOST.’…it became clear to me that they view jobs as lollipops, things you give out to good boys and girls,” said Cohen, who would not identify his friend.

Cohen also said the transition official was “completely dismissive” of concerns raised about Trump’s appointment of Bannon, who Trump’s advisors have strongly defended.

His friend’s email conveyed the feeling that ‘we’re so glad to see the bicoastal elites get theirs,’” added Cohen, who described the response as “unhinged.’’

Trump transition officials had no immediate comment Tuesday, but Jason Miller, a senior transition communication adviser, told reporters Monday night that Trump and Pence know the urgency of filling key positions.

“Obviously, inauguration day is not getting further away. And people need to get going. This is an absolute top priority understood by the president-elect and the vice president-elect,” Miller said.

As for the president-elect, Trump jumped back on Twitter Tuesday morning to argue about his expected loss of the popular vote to Hillary Clinton. Trump was known for his incendiary tweets during the campaign, but has tweeted only sporadically since his victory.

“If the election were based on total popular vote I would have campaigned in N.Y., Florida and California and won even bigger and more easily,” Trump wrote at his personal account, @realDonaldTrump.

Six minutes later, Trump changed his tone and defended the electoral college, where his victory was secured. The system is “actually genius in that it brings all states, including the smaller ones, into play. Campaigning is much different!” he wrote.

Amid the widespread uncertainty, coordination between Trump’s transition team and the Obama White House is now on hold until Trump’s team signs a key document, the Associated Press reported. The document, a memorandum of understanding smoothing interaction between the two teams, has yet to be signed by Pence, who recently replaced New Jersey Gov. Chris Christie (R) as head of Trump’s transition planning.

White House spokeswoman Brandi Hoffine said the Obama administration is working with Trump advisers to get the document signed.

The cascading developments followed a telephone call Monday between Trump and Russian President Vladimir Putin, during which they agreed that relations between their countries were “unsatisfactory” and vowed to work together to improve them, the Kremlin said in a statement.

Moscow said the two men discussed combining efforts in the fight against terrorism, talked about “a settlement for the crisis in Syria” and agreed that their aides would begin working on a face-to-face meeting between them.

Trump’s office later said that Putin had called to “offer his congratulations” and that they had discussed shared threats and challenges, “strategic economic issues” and the long-term relationship between the two nations.

The president-elect spoke admiringly of Putin during the campaign, praising him as a stronger leader than President Obama and saying the two countries should join together to fight terrorists, particularly the Islamic State in Syria.

Those views put Trump at odds with many GOP defense hawks, who are uniformly suspicious of Moscow and have denounced Russian actions in Eastern Europe, Ukraine and Syria. The offer of cooperation could also immerse Trump in a deep controversy with the Pentagon, where military and civilian leaders have strongly opposed collaboration with Russia, particularly in Syria.

Protests, meanwhile, continued for a sixth straight day in major cities and on college campuses over last week’s election results, in which Trump won the electoral college but lost the popular vote to Democratic nominee Hillary Clinton.

Andrew Roth in Moscow and Elise Viebeck and Jenna Johnson in Washington contributed to this story.