Libby, 56, once one of the most trusted aides to US Vice President Dick Cheney, was convicted in March for perjury and obstruction in a case probing whether White House officials leaked the name of CIA officer Valerie Plame.

Libby was also fined 250,000 dollars by the court on Tuesday.

He told Judge Reggie Walton he hoped the court would "consider, along with the jury verdict, my whole life" in determining an appropriate sentence.

But the tough sanction handed down was in line with the 30-to-37 month term sought by special prosecutor Patrick Fitzgerald, and with federal guidelines.

"It needs to make a clear statement that truth matters and one's status in life does not," Fitzgerald told the judge ahead of the verdict.

Walton acknowledged Libby's contribution to national security following the terrorist attacks on the United States on September 11, 2001. But he added: "we expect and demand a lot from people ... who have the welfare and security of the nation in their hands."

Cheney branded the jailing of his trusted former aide a "tragedy," and voiced hope the sentence would be revised.

Libby was found guilty of lying about conversations he had about Plame, but not of leaking her name. The leak allegedly aimed to avenge criticism of the White House's rationale for war with Iraq by Plame's ex-diplomat husband, Joseph Wilson.