The comments from prominent Republicans follow revelations that Sessions met with the Russian ambassador during election season. Under oath in front of the Senate Judiciary Committee for his confirmation hearing in January, Sessions said that he had not met with any Russian officials.
[Sessions met with Russian envoy twice last year, encounters he later did not disclose]
According to Justice Department officials, Sessions, a top Trump supporter, met with Russian Ambassador Sergey Kislyak twice in 2016, including a private meeting in September in his office.
In a statement following the revelations, Sessions denied he had met with "any Russian officials to discuss issues of the campaign. I have no idea what this allegation is about. It is false," he said.=
On Thursday morning, Sessions told NBC News, "I have said whenever it's appropriate, I will recuse myself. There's no doubt about that."
White House Press Secretary Sean Spicer dismissed calls for Sessions's recusal as politically motivated.
"There's nothing to recuse himself," Spicer said in an interview on Fox News. "He was 100 percent straight with the [Judiciary] committee and I think that people who are choosing to play partisan politics with this should be ashamed of themselves."
[Trump's hard-line actions have an intellectual godfather: Jeff Sessions]
House Speaker Paul D. Ryan (R-Wis.) agreed, noting that ongoing investigations have so far found no evidence that "an American or a person in the Trump campaign was involved or working with the Russians."
"Should he recuse himself? I think he answered that question this morning," Ryan told reporters during his weekly news conference. "If he himself is the subject of an investigation, of course he would. If he is not, I don't see any purpose or reason for doing this."
House Majority Leader Kevin McCarthy (R-Calif.) shared conflicting views on Sessions during back-to-back television interviews on Thursday. Asked whether Sessions should recuse himself in this situation, McCarthy told MSNBC's "Morning Joe," "I think the trust of the American people - you recuse yourself in these situations, yes."
Pressed a second time about whether he was calling for Sessions to recuse himself, McCarthy said, "I think it would be easier from that standpoint, yes."
But McCarthy later said his comments had been misinterpreted, telling Fox News, "I'm not calling on him to recuse himself. I was asked on 'Morning Joe,' if he needs to recuse himself as going forward. As you just heard, Attorney General Sessions said he would recuse himself going forward - appropriate, and that's all my answer was."
The debate marks the second time that a senior Trump administration official has come under scrutiny for his comments about contact with the Russians. Last month, Trump fired his national security adviser, Michael T. Flynn after The Washington Post reported that he had misled the administration, specifically Vice President Pence, regarding his contacts with Russian officials. Before news of those contacts surfaced, Pence had defended Flynn in a television interview.
The revelation that Flynn had lied to Pence prompted a number of congressional Republicans, including Senate Armed Services Committee Chairman John McCain (R-Ariz.), to call for his resignation.
Sessions has focused his response to the allegations on the substance of his conversations with Kislyak, which he said did not veer into the realm of discussing the campaign.
Many Democrats considered that a direct contradiction of Sessions's testimony in January, when he told Sen. Al Franken (D-Minn.) that he did not speak to Russian officials.
But Sen. Lindsey Graham (R-S.C.), who counts himself a close friend of Sessions, said "I don't think Jeff Sessions is a liar" and argued he had not misled the Judiciary Committee "because all of the questions were about campaign contacts."
Graham said on Thursday that Sessions should remove himself from the decision-making chain only "if there ever becomes enough evidence to suggest prosecution or possible criminal prosecution" of someone in the Trump team is necessary because Sessions had close ties to the campaign.
Sessions "does owe it, quite frankly, to all of us to tell us what he talked about" with Kislyak," Graham said.
Senators who deal regularly with defense, foreign affairs or intelligence matters often meet with foreign officials. In a statement defending Sessions, Sen. Roy Blunt (R-Mo.), a member of the Intelligence Committee, said Thursday that he has spoken with at least 20 ambassadors in the last six weeks.
But as a member of the Senate Armed Services Committee, Sessions was less likely to meet with foreign ambassadors than foreign military leaders. The Washington Post has spoken with all but two senators - or their staffers - that served on the armed services panel in 2016. All of them said they had not met with Kislyak last year.
Senate Foreign Relations Committee Chairman Bob Corker (R-Tenn.) said he met with Kislyak in 2016, but in the earlier part of the year before the presidential campaign intensified.
Some senior Democrats agreed on Thursday that there's nothing unusual about lawmakers interacting with foreign diplomats - but said that Sessions needs to be removed from any oversight of investigations of Russia's alleged interference.
"It would be of Alice in Wonderland quality if this administration were to sanction him to investigate himself," Senate Minority Leader Charles E. Schumer (D-N.Y.) told reporters as he joined other Democrats in calling on Sessions to resign.
House Minority Leader Nancy Pelosi (D-Calif.) said in a statement released late Wednesday that "Sessions is not fit to serve as the top law enforcement officer of our country." On Thursday, she told reporters that he "lied under oath" to senators about his contacts with Kislyak.
Pelosi's comments prompted dozens of House Democrats to call for Sessions's ouster. Rep. Elijah E. Cummings (D-Md.), the top Democrat on the House oversight panel, faulted Sessions for keeping "secret" his conversations with Kislyak even after Flynn was fired.
But in an acknowledgment that Sessions is unlikely to step down, Schumer and other Democrats focused mostly on ensuring impartial investigations of Russia's meddling in U.S. elections.
"Better for the country if he resigns, but let's get an investigation going," he said.
Schumer said that the Justice Department's inspector general should carry out an investigation of Sessions himself regarding any previous communications with Russian officials and what related steps, if any, he has taken since assuming leadership of the department.
Though Congress has the power to appoint a special prosecutor, it has traditionally deferred the choice to Justice Department officials. This time, however, Democrats want to ensure that a non-political Justice Department official makes the selection.
The second in command at the Department of Justice is Dana Boente, an Obama-appointed U.S. Attorney for the Eastern District of Virginia who Trump tapped to serve as Acting Attorney General when he fired former Acting Attorney General Sally Yates.
Schumer called for legislation to give Congress a better backstop, if lawmakers aren't satisfied with the choice, by rewriting the independent counsel law. The new legislative proposal would be more narrowly tailored than the previous independent counsel law that has long since expired. Under the new Democratic plan, a three-judge panel would be tasked with appointing the prosecutor, according to Schumer aides.
Mike DeBonis, Adam Entous and Ellen Nakashima contributed to this report.
