Washington • The FBI investigation meant to defuse the explosive conflict over Supreme Court nominee Brett Kavanaugh sparked a new round of partisan combat Sunday, as the White House appeared to retain sharp limits on the probe even as President Donald Trump and Republican officials publicly suggested otherwise.

Two Trump administration officials said Sunday that White House had not placed any limits on the FBI investigation into claims of sexual assault leveled against Kavanaugh but was also opposed to a "fishing expedition" that could take a broader look at Kavanaugh's credibility and behavior.

The statements, made by press secretary Sarah Huckabee Sanders and presidential counselor Kellyanne Conway in television interviews, followed reports that federal investigators are pursuing allegations made by two women but not a third, Julie Swetnick, who signed a sworn affidavit accusing Kavanaugh of sexually aggressive behavior and being present at parties where gang rapes occurred.

Trump himself tweeted late Saturday that he wanted FBI agents "to interview whoever they deem appropriate, at their discretion."

But a senior U.S. official, requesting anonymity to describe internal conversations, confirmed Sunday that Swetnick is not expected to be interviewed and said interviews pertaining to the other allegations will be limited to Kavanaugh, the first two accusers and people who have been identified as present for the incidents.

Sen. Lindsey Graham, R-S.C., a member of the Senate Judiciary Committee, described a similar witness list in television appearances Sunday.

White House counsel Donald McGahn is most directly involved in guiding the investigation and has been in frequent touch with Republican senators about its scope, the administration official said, adding that the administration is hoping a report could be filed even sooner than the Friday deadline.

Several Democrats warned this weekend against too many limits on the purview of the investigation.

"They ought to be doing multiple investigations at the same time," Sen. Chris Coons, D-Del., a Judiciary Committee member, said in an MSNBC interview Saturday. "There are multiple allegations currently in front of the committee, and I think it is not hard to figure out the universe of witnesses. It is not 500. It may not be 50. But it has to be more than five."

White House spokesman Raj Shah said Sunday that Democrats are "merely attempting to further delay and politicize" the investigation. And Trump, in a shift in tone from the night before, tweeted Sunday afternoon that Democrats are "are starting to put out the word that the 'time' and 'scope' of FBI looking into Judge Kavanaugh and witnesses is not enough. Hello! For them, it will never be enough - stay tuned and watch!"

The squabbling added to the swirl of public confusion over the parameters of the FBI inquiry and who is setting them. The order to the FBI was signed by Trump but has not been made public. White House officials have sought to lay responsibility for the details on either the Senate or the FBI.

The president's Saturday tweet also sparked confusion in the FBI, which had previously been told only to conduct a limited investigation of particular allegations, a person familiar with the matter said. It was unclear Sunday whether there had been more communications between the White House and the FBI clarifying what agents should look into.

The only official description of parameters has come from Judiciary Committee Chairman Chuck Grassley, R-Iowa, who said Friday the FBI probe would be no more than a week long and would be limited solely to "current credible allegations" against Kavanaugh.

Grassley and other senators have provided few other specifics, and a committee spokesman declined to comment after Trump's tweet Saturday endorsing a broader approach. A spokesman for Senate Majority Leader Mitch McConnell, R-Ky., also declined to provide more information Sunday about the probe's boundaries, though McConnell's office circulated materials seeking to undermine Swetnick's credibility.

Sanders said on "Fox News Sunday" that the White House is "not micromanaging this process" but also said a probe into Swetnick's claims and whether Kavanaugh may have misled lawmakers in his Senate testimony would not be acceptable.

"The Senate is dictating the terms. They laid out the request, and we've opened it up," she said, adding, "This can't become a fishing expedition like the Democrats would like to see it be."

Conway said on CNN's "State of the Union," "It's not meant to be a fishing expedition." She added that who will be interviewed was "up to the FBI" in its expanded background investigation into Kavanaugh.

Thursday's riveting hearing, featuring testimony from California professor Christine Blasey Ford about her allegations that Kavanaugh assaulted her when both were high school students in the early 1980s, prompted several wavering Republican senators to demand a more thorough federal probe of the alleged incident.

The FBI had not yet contacted Ford for an interview, one of her advisers said Sunday afternoon. An FBI spokeswoman declined to comment Sunday.

At the hearing, Kavanaugh angrily and categorically denied assaulting Ford or any other woman. Two others, Swetnick and Debbie Ramirez, have publicly come forward to accuse Kavanaugh of sexual misconduct.

Ramirez alleges that Kavanaugh, as a Yale University freshman, drunkenly exposed himself and shoved his penis in her face in front of a group of classmates, according to an account she gave to the New Yorker. Her attorney said Saturday that the FBI had contacted Ramirez about an interview and that she planned to cooperate.

Swetnick's accusations, brought forward in a sworn statement by lawyer and potential 2020 presidential candidate Michael Avenatti, have been treated much more gingerly, including by Democrats, due to a lack of corroboration.

Senate Democrats have put special emphasis on having the FBI interview the people Ford says were present for the party where the alleged assault took place — particularly Mark Judge, the high school classmate of Kavanaugh’s who Ford says was in the room for the incident. Judge has said in written statements that he does not recall the incident; Senate Republicans declined to call him to testify. Two others said by Ford to have been present for the party have also said they do not recall it.

Many Democrats have called for the FBI to take a broader look at whether Kavanaugh may have misled senators by minimizing his carousing behavior in high school and college or by mischaracterizing entries in his high school yearbook that could indicate a penchant for drunken and misogynistic behavior.

Sen. Amy Klobuchar, D-Minn., speaking on CNN, said Kavanaugh's claims that he had never blacked out or suffered any memory loss while drinking don't "quite make sense to me" and said she hoped the FBI would interview friends to determine whether that was credible.

She added that the FBI could also interview high school friends of Kavanaugh's to determine whether his innocent explanations for portions of his yearbook entry are accurate.

"I've never heard that the White House, either under this president or other presidents, is saying: 'Well, you can't interview this person; you can't look at this time period; you can only look at these people from one side of the street,'" she said. "I mean, come on."

Graham said the parameters of the probe are based on the wishes of three wavering Republican colleagues — Sens. Jeff Flake of Arizona, Susan Collins of Maine and Lisa Murkowski of Alaska — for a “limited review.”

“They wanted ... the FBI to talk with the witnesses that Dr. Ford named,” he said Sunday on ABC’s “This Week.” “They want to talk to Ms. Ramirez, because she refused to talk to the committee. They’re going to Mark Judge — ‘Did you ever see Brett Kavanaugh drug women or engage in gang rape?’ I think that’s going to be the focus of it.”

Collins said in a statement Sunday that she is "confident that the FBI will follow up on any leads that result from the interviews."

Aides to Flake and Murkowski did not respond to messages sent Sunday asking about their own expectations for the new review.

Flake, who prompted the new FBI probe by threatening to withhold his vote to confirm Kavanaugh, said in a "60 Minutes" interview set to air Sunday that he found Kavanaugh's testimony Thursday to be "partisan" at times and that "his interaction with some of the members was a little too sharp."

But, he said, he understood his anger. "If I was unjustly accused, that's how I would feel, as well," Flake said.

Both Sanders and Conway on Sunday floated a theory, circulating in conservative circles for weeks, that Ford was in fact assaulted by someone else. Republicans on the Senate Judiciary Committee said last week they interviewed two men who said they might have had the encounter with Ford that she described, but no Republican senator has lent any credence to those claims.

Ford testified Thursday that she was "100 percent" certain that Kavanaugh, not another man, assaulted her in 1982. Kavanaugh, testifying hours later, said he was "100 percent" certain that he was innocent of the accusation.

“Nobody could deny that her testimony wasn’t compelling, that it wasn’t impactful,” Sanders said. “I do think the big question is, was that Brett Kavanaugh?”