WASHINGTON — Vice President Cheney’s former chief of staff, I. Lewis Libby Jr., faces two-and-a-half years in prison as punishment for lying to a grand jury and the FBI during an inquiry into the leaked identity of a CIA officer.

Telling Libby he had “failed to meet the bar,” U.S. District Judge Reggie Walton sentenced him to a prison term that fell within recommendations offered by the government, ignoring pleas from the defense that Libby’s long service to the nation merited leniency and probation over a jail sentence.

A jury convicted Libby in March of four felony counts of obstruction of justice, perjury, and making false statements. He is planning an appeal, and he will likely remain free for at least the next several weeks. A hearing is set for June 14 to determine if he can stay out of prison for the duration of the appeal process. The judge yesterday appeared disinclined to grant Libby bail.

“Evidence in this case overwhelmingly indicated Libby’s culpability,” Judge Walton said in sentencing the former top White House aide. The judge also fined him $250,000.

Some conservatives have called on President Bush to pardon Libby, but that possibility appeared unlikely. A White House spokeswoman, Dana Perino, told reporters yesterday that the president would not intervene in the case while an appeal is ongoing. “The president said he felt terrible for the family, especially his wife and his kids,” Ms. Perino said while traveling with Mr. Bush in Europe.

Flanked by his attorneys, Libby, 56, stood facing the bench as Judge Walton delivered his sentence inside the E. Barrett Prettyman Federal Courthouse. The defendant often took notes during his trial, but he sat quietly and attentively for the three-hour hearing yesterday.

Before the judge sentenced him, Libby made brief remarks in which he thanked the court personnel for showing him “nothing but kindness” during the long hours he spent in the courthouse during the past year. He acknowledged that the judge would have to set his punishment, but he made no specific reference to the crimes of which he was convicted. “It is, respectfully, my hope that the court will consider, along with the jury verdict, my whole life,” Libby said in a soft, even voice.

The vice president issued a statement yesterday calling Libby “a friend” and “a man of the highest intellect, judgment, and personal integrity.”

Referring to Libby’s plan to appeal, Mr. Cheney said of himself and his wife: “Speaking as friends, we hope that our system will return a final result consistent with what we know of this fine man.”

The sentencing represents the latest chapter in a story that began as a probe into who in the government leaked the identify of a CIA officer, Valerie Plame. Her name surfaced in a column in July 2003 by Robert Novak shortly after her husband, Joseph Wilson IV, a former diplomat, went public with criticisms of the intelligence the Bush administration used to justify the invasion of Iraq. Libby was not charged with the leak but with lying to federal investigators and a grand jury about conversations he had with reporters about Ms. Plame.

The defense had argued that some of Libby’s false statements were attributable to a faulty memory. Lawyers for each side yesterday also tangled over the relevancy of whether Ms. Plame’s CIA status was covert. Judge Walton had ruled it irrelevant to the central arguments in the trial, but he said yesterday that even if Libby did not know of her status, he should have been more careful in discussing it with reporters.

The judge’s sentence followed impassioned pleas by each side. The special prosecutor, Patrick Fitzgerald, who has maintained that Libby’s lies created a “hall of mirrors” that ruined his investigation into the leak, urged Judge Walton to “make a clear statement that truth matters, that truth matters more than anything else.”

“If we lose the truth in the judicial system, then the judicial system is lost,” the prosecutor told the court.

The prosecution pushed the judge to follow sentencing guidelines and impose a 30- to 37-month prison term for Libby. The lead defense attorney, Theodore Wells Jr., asked him to break from those guidelines in consideration of what he described as Libby’s “exceptional” record of public service. A lot of lawyers come from privileged backgrounds and “do squat for their country,” Mr. Wells said. Libby was not one of them, he said.

Mr. Wells read aloud from a handful of the letters that administration officials submitted on Libby’s behalf, and he even provided the judge a copy of a Distinguished Service Award that Libby received in 1993. Mr. Wells also cited the “public humiliation” Libby has endured due to negative coverage in the press. “He has fallen from public grace,” Mr. Wells said. “It is a tragic fall, a tragic fall.”

In handing down the sentence, Judge Walton said he had read the letters about Libby and that his record of service “weighed heavily in his favor.” But while the judge said he had “the highest respect” for people who work to protect the country, he added, “I also think it is important we expect and demand a lot from people who put themselves in those positions.”

“Libby failed to meet the bar,” Judge Walton said. “For whatever reason, he got off course.”

In arguments over Libby’s punishment, the defense argued that the absence of even an indictment involving the leak itself should have led to a lesser sentence for Libby under federal guidelines.

Judge Walton rejected that argument, agreeing with Mr. Fitzgerald that Libby’s lies may well have prevented the prosecution from fully pursuing the leak. “If someone’s successful in their efforts” to deceive or throw off investigators, the judge said, “you may never know if there was an offense or not.”

Neither Libby nor his attorneys spoke to reporters as they left the courthouse yesterday. As he passed a throng of cameramen and climbed into a black sedan, two women from the anti-war group Code Pink Women for Peace shouted at him. “Go right to jail, Libby! You criminal,” one of the women, Medea Benjamin of San Francisco, said.