WASHINGTON, Nov. 3 (Xinhuanet) -- US Vice President Dick Cheney's former chief of staff and national security adviser Lewis "Scooter" Libby on Thursday pleaded not guilty to charges which stem from the CIA leak scandal.

    In his first court appearance after being indicted on one perjury and other four charges last Friday stemming from a 22-month probe into the case of unmasking the identity of a undercover CIA agent, Libby showed his determination to fight a long legal battle which could take several years.

    "With respect, your honor, I plead not guilty," Libby told federal Judge Reggie Walton after being asked how he would plead on the five charges during a brief arraignment.

    A full status hearing for the case is scheduled for Feb. 3 nextyear, while Cheney and other top White House officials could be summoned to testify.

    If convicted, Libby could face a maximum of 30 years in prison,but before any trial he could still try to reach a deal with prosecutors on lesser charges.

    US President George W. Bush's top political adviser Karl Rove, who was also implicated in the scandal, was not indicted along with Libby, but is still under investigation of how the identity of covert CIA agent Valerie Plame was exposed.

    Special Counsel Patrick Fitzgerald, who oversees the investigation of the case, is expected to inform Rove his decisionin next few weeks.

    The case puts a spotlight on the White House's use of prewar intelligence on Iraq because Plame's identity was leaked to the media in 2003 July after her diplomat husband, Joseph Wilson, accused the Bush administration of twisting intelligence on weapons of mass destruction to justify the war on Iraq.

    Wilson has accused Rove and other White House aides of intentionally leaking his wife's identity to punish him.

    Libby's indictment and the leak case could cause more damages to the Bush administration, which was already reeling from the increasing US death toll in Iraq, the slow response to hurricane disaster and the withdrawal of US Supreme Court nominee Harriet Miers under fire from the president's own Republican camp. Enditem