WASHINGTON—Ambassador Susan Rice's attempt to repair her standing with Senate Republicans fell short Tuesday, as a trio of GOP senators emerged from a meeting with her even more harshly critical of the comments she made following the U.S. consulate attack in Libya.

One of the senators, Kelly Ayotte of New Hampshire, said she would try to block the confirmation of Ms. Rice or another nominee to succeed departing Secretary of State Hillary Clinton. "My view is we should hold on this until we get sufficient information," she said.

Ms. Ayotte and Sens. John McCain of Arizona and Lindsey Graham of South Carolina said the meeting on Capitol Hill left them more concerned than ever about the public statements Ms. Rice made in the wake of the Sept. 11 attacks in Benghazi, Libya, where U.S. Ambassador Christopher Stevens and three other Americans were killed. "All I can say is that the concerns I have are greater today than they were before," Mr. Graham said after the meeting. "We're not even close to getting the basic answers."

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Ms. Rice, the ambassador to the United Nations, is seen as a front-runner to succeed Mrs. Clinton. In a statement issued after the meeting, Ms. Rice conceded that part of her comments about the attack in several television interviews days afterward were incorrect, but said they were based on evolving intelligence.

In the interviews, Ms. Rice said the attack grew out of protests over an anti-Islamic video; officials later said there was no protest in Benghazi that day.

"The talking points provided by the intelligence community, and the initial assessment upon which they were based, were incorrect in a key respect: There was no protest or demonstration in Benghazi," she said in her statement. Ms. Rice added that she didn't intend to mislead and said "the administration updated Congress and the American people as our assessments evolved."

Mr. McCain said he was "troubled" by what he heard, and Ms. Ayotte said there was clear evidence early on that people tied to al Qaeda had carried out the Libya attack.

Sens. McCain and Ayotte issued a statement late Tuesday saying Michael Morell, acting director of the Central Intelligence Agency, told lawmakers in the closed session that the Federal Bureau of Investigation removed references to al Qaeda in talking points prepared by the CIA. Senators said the CIA later corrected Mr. Morell's statement and said that the CIA, not FBI, had removed the references.

"We are disturbed by the administration's continued inability to answer even the most basic questions," the senators said.

A U.S. intelligence official confirmed that the CIA made the edit that substituted "extremists" for "al Qaeda."

The official said the change was made for "valid intelligence and investigatory reasons." The CIA was seeking to protect the sources of classified information, the al Qaeda links at the time were "tenuous," and there were concerns about prejudicing the FBI's criminal investigation, the official said.

The talking points, the official said, were written to provide lawmakers and senior officials guidance on what they could say preliminarily about the attacks in public.

"They were never meant to be definitive and, in fact, noted that the assessment may change. The points clearly reflect the early indications of extremist involvement in a direct assault," the official said. "It wasn't until after they were used in public that analysts reconciled contradictory information about how the assault began. Finding the right balance between keeping the public informed and protecting sensitive information is never easy, and that was true here. There was absolutely no intent to misinform."

Criticism of Ms. Rice by the Republican senators had appeared to be abating, but the Tuesday meeting rekindled hostilities. That may complicate her chances for the secretary of state slot. Massachusetts Sen. John Kerry, a Democrat, is another possibility for the job. President Barack Obama may announce his choice as soon as this week.

The administration may have erred by letting Ms. Rice seek amends with lawmakers so soon, according to Lawrence Korb, senior fellow at the Center for American Progress, a think tank with ties to the White House. "They probably should have waited until they had a formal nomination before they did it," he said. "Then, you have the president's prestige on the line."

Administration officials were surprised by the ferocity of the Republican criticism that followed the closed-door session, saying it didn't match the tone of the meeting, which had few fireworks or surprises. They had hoped her appearance would ease tensions, and they accused Republicans of stepping up their attacks for political reasons.

The officials noted that the three Republicans stopped short in the meeting and afterward of repeating a pledge to do anything in their power to stop Ms. Rice's nomination, if Mr. Obama taps her for the post.

The officials said Sen. Joe Lieberman (I., Conn.) got a similar briefing by Ms. Rice and Mr. Morell Tuesday and then came to the defense of Ms. Rice, saying she acted appropriately.

During the sessions, Mr. Morell said the talking points used by Ms. Rice closely tracked the CIA's classified intelligence reports at the time, an administration official said.

White House press secretary Jay Carney questioned the focus on Ms. Rice's TV appearances. The Sunday shows "have almost nothing to do—in fact, zero to do—with what happened in Benghazi," Mr. Carney said on Tuesday. The president's focus, he said, is bringing those who killed Americans to justice and averting future attacks.

The Libya attacks and the administration's handling of them are being investigated by several congressional committees, the FBI and a State Department panel.

—Peter Nicholas

and Adam Entous

contributed to this article.

Write to Sara Murray at sara.murray@wsj.com