In Donald Trump's Washington, there are many people vying for the President-elect's attention. The Washington Post's Robert Costa explains how Trump will seek advice during the transition. (Bastien Inzaurralde,Victoria Walker/The Washington Post)

President-elect Donald Trump plans to meet this weekend with former Massachusetts governor Mitt Romney, a fierce critic during the campaign, to discuss his transition operation and a potential role as secretary of state, people close to the transition said Thursday.

Trump’s outreach to Romney, the 2012 Republican presidential nominee, could help bridge the divide between the president-elect’s advisers and the GOP establishment, and send a signal to foreign capitals that Trump is interested in a more conventional figure as the nation’s top diplomat.

Late Thursday night, Trump offered the national security adviser post to retired Lt. Gen. Mike Flynn, according to a person close to the transition team.

Also Thursday, Newt Gingrich, the former Republican House speaker, said in an interview with McClatchy News Service that he would not have an official role in Trump’s administration, despite having previously been identified as a potential secretary of state. Gingrich confirmed the report in an interview with The Washington Post.

“I think it’s good that the president-elect is meeting with people like Mr. Romney,” Sen. Jeff Sessions (R-Ala.), who also is being considered for Trump’s Cabinet, told reporters outside Trump Tower in New York. “He’s meeting with a lot of talented people that he needs good relationships with. I think Mr. Romney would be quite capable of doing a number of things, but he’ll be one of those I’m sure that’s reviewed, and Mr. Trump will make that decision.”

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The disclosure of their meeting came as something of a surprise. Romney had been one of the earliest and most vocal critics of Trump among the GOP leadership, ripping the real estate mogul last March after squelching speculation that he would mount a late primary challenge to Trump.

“If we Republicans choose Donald Trump as our nominee, the prospects for a safe and prosperous future are greatly diminished,” Romney said, adding that “dishonesty is Trump’s hallmark.”

Romney also criticized Trump for racially charged campaign rhetoric, prompting Trump to write on Twitter that “Mitt Romney had his chance to beat a failed president but he choked like a dog. Now he calls me racist — but I am least racist person there is.” Romney took a more tempered tone after Trump’s general election triumph last week, and called him to offer his congratulations.

The news came as Trump’s transition to power kicked into higher gear. Transition officials were expected to fan out across federal agencies, and Trump prepared for an important meeting with Japan’s prime minister.

The 5 p.m. session with Japanese Prime Minister Shinzo Abe, Trump’s first with a foreign leader since the election, has raised questions among some in Washington’s foreign policy community because Trump has apparently not been briefed by the State Department. Officials said Wednesday that the transition team has not reached out to State.

A former State Department official said such a meeting with a foreign leader would normally be preceded by numerous briefings from key diplomats, which is considered especially important here because the Japanese are concerned about comments Trump made on the campaign trail. The president-elect repeatedly said that Japan should pay more for its own defense and be less reliant on the United States.

“The world does not stop for the transition,’’ said the official, who spoke on condition of anonymity to speak freely. Trump “would want an intelligence briefing. You’d probably want to get briefed on what’s what happening in the region.’’

But Trump’s campaign manager, Kellyanne Conway, said Thursday that the session at Trump Tower, which Vice President-elect Mike Pence will attend, will be “much less formal” than in the future because Trump has yet to assume office. “We are very sensitive to the fact that President Obama is still in office for the next two months,’’ Conway said.

As Trump remained ensconced with close aides in his Manhattan office tower, his transition team appeared to signal Thursday that Sessions is a leading candidate to be attorney general.

“The President-elect has been unbelievably impressed with Senator Sessions and his phenomenal record as Alabama’s Attorney General and U.S. Attorney,’’ the team said in a statement about Trump’s meeting with Sesisons on Wednesday. While the statement cautioned that “nothing has been finalized,’’ Sessions’s 14-year stint in those two posts in the 1980s and 1990s would be his primary qualifications to lead the Justice Department.

Sessions’s former staff director of the Senate Judiciary Committee, Brian Benczkowski, is also helping to manage the Justice Department transition for Trump’s team, lawyers familiar with the matter have said.

Sessions, a top Trump adviser known for his hardline views on immigration, has been a rising force in the transition team and is also under consideration for defense secretary. His nomination for Justice would likely bring a re-examination of his failed nomination by President Ronald Reagan in 1986 to be a federal judge.

A bipartisan panel of senators on the Judiciary Committee declined to send his nomination to the Senate floor that year amid allegations that he had made what some characterized as racist remarks. Sessions, who has been a senator for 20 years, has vehemently denied holding any racist views and has said he supported civil rights in Alabama, where he grew up outside of Selma.

Trump’s meeting with Abe arose from a phone conversation between the Japanese leader and Trump. When Abe called to congratulate Trump shortly after his victory, he mentioned that he would be passing through New York this week and suggested a meeting. “That would be awesome,” Trump immediately responded, according to people briefed on the conversation.

The two leaders have much to discuss. Trump has vowed to scrap the Trans-Pacific Partnership trade deal that Abe recently pushed through his parliament. And the president-elect caused jitters in both Japan and South Korea during the campaign by saying both nations were not paying enough for their defense and that he would make them pay more — perhaps even all — of the costs of hosting U.S. military bases.

Since Trump’s victory, the Japanese government has been taking a wait-and-see approach. “Trump said various things during his campaign, but I will not presuppose what he will do as president,” Tomomi Inada, Japan’s defense minister, said late last week. She added, however, that Japan is paying its fair share toward base costs.

In a new development Thursday, Trump’s transition team announced that anyone serving in the new administration would be banned for life from lobbying for any foreign government. Trump had proposed such a ban in an ethics plan he unveiled last month, but it is unclear how the ban would be implemented.

There is no current law that imposes a lifetime ban on post-government employment for administration officials, with one exception — there is a lifetime ban on certain members of the U.S. Trade Representative’s Office from representing foreign governments after leaving the agency. The reasoning is to prevent them from essentially “switching sides” and using the knowledge they gained while representing U.S. interests to weaken or amend the agreement to the benefit a foreign country.

A lifetime ban like the one Trump proposed raises constitutional issues, and would have to be more narrowly tailored to pass muster in the courts — for example, if the ban was limited to certain State Department or Defense Department officials whose jobs involved working closely with foreign governments. But a blanket lifetime ban could be unconstitutional.

“Lifetime bans are really problematic from a legal standpoint because it prevents people from making a living,” said Brett Kappel, a political law and government ethics attorney. “A lifetime ban on anybody in the administration ever becoming a representative of a foreign government? I don’t see how that would hold up in court.”

It is also unclear whether the ban would be implemented by legislation or executive order.

Meanwhile, the pace of the transition appeared to quicken. Offices prepared for Trump’s teams in departments and agencies across the government had remained empty Wednesday. But the White House said that it received paperwork, signed Tuesday evening by Vice President-elect Mike Pence, necessary for the teams to move into the department offices and begin to receive briefings from current officials.

The names of people on the “landing teams” for the State Department, the Justice Department, the Pentagon and the National Security Council will be submitted to the White House on Thursday and announced Friday, the transition team said Thursday in a conference call with reporters. Economic policy landing teams will be announced Monday, followed by teams devoted to domestic policy and independent federal agencies.

The transition released a list of 29 presidents and prime ministers with whom it said Trump and Pence have spoken since the election. And transition communications director Jason Miller said that reports of turmoil within the transition following the ouster of several senior team members in recent days came largely from “folks on the outside” and those who feared that Trump was preparing to “drain the swamp, as he’s promised.”

Miller declined to speculate on the timing of appointment announcements, saying that “the president-elect is going to get this right” and that names would be put forward when Trump was ready. He also denied reports that Jared Kushner, Trump’s son-in-law, had been instrumental in purging members of the transition seen as close to New Jersey Gov. Chris Christie, whom Pence replaced as the head of the team last week.

Miller said Trump met with several advisers and candidates for administration positions Wednesday, including Rep. Tom Price (R-Ga.), investor Steve Feinberg, Success Academy Charter Schools chief executive Eva Moskowitz and Rep. Mike Pompeo (R-Kan.). Miller did not elaborate on which people on the list are candidates to join the administration. Price is considered a candidate to lead the Department of Health and Human Services.

Trump will meet Thursday with South Carolina Gov. Nikki Haley, Rep. Jeb Hensarling (R-Tex.), Florida Gov. Rick Scott, former secretary of state Henry Kissinger and retired Gen. Jack Keane, among others, Miller said.

Attention continued to be mainly focused on potential national security picks. Trump campaign surrogates said former New York mayor Rudolph W. Giuliani remained at the top of the rumored list for secretary of state, along with former State Department official John Bolton. Sen. Tom Cotton (R-Ark.), who visited Trump on Tuesday in Manhattan, emerged as a defense secretary candidate.

Farther down the defense list were George W. Bush national security adviser Stephen V. Hadley and former senator James M. Talent (R-Mo.). Frank Gaffney, a far-right conspiracy theorist who was described in some media reports as a Trump transition adviser and possible pick for a national security job, said Wednesday that he had “not been contacted by anyone from the team.” His statement followed one by Miller, the transition communication chief, that Gaffney is “a nice guy, but he’s not part of the transition team” and was not advising it.

House Intelligence Committee Chairman Devin Nunes (R-Calif.), mentioned as a possible CIA director after the leading candidate, former chairman Mike Rogers of Michigan, was among those purged early this week, is a transition adviser but is “not interested in a post,” a congressional aide said. Former congressman Pete Hoekstra, also a Michigan Republican and a former committee chairman, said in an interview that he’d told the transition “if they have a role for me, I’d be more than happy to discuss it with them.”

Hoekstra said the Trump team was “going to expand its outreach, absolutely. But they’re going to do it in a methodical way.”

Despite intense media scrutiny and swirling rumors in Washington, Trump’s timetable was still well within the bounds of his immediate predecessors. Obama did not announce his first Cabinet pick until nearly a month after the 2008 election; he presented his national security team en masse Dec. 1 that year. Confirmation of George W. Bush’s 2000 victory did not come until a Supreme Court decision more than a month after the Nov. 7 election.

Anna Fifield in Tokyo and Catherine Ho, Sari Horwitz, Dan Lamothe, Greg Miller, Ellen Nakashima, Philip Rucker, Missy Ryan, Julie Tate and Elise Viebeck in Washington contributed to this report.