With only days left until the federal grand jury closes its probe of a CIA leak believed to have originated in the White House, President Bush declined again Monday to speak about the case.

"This may be the fourth time I've been asked about this, which I appreciate; you're doing your job. I'm not going to comment about it," Bush said during a question-and-answer session with reporters after a Cabinet meeting.

Click in the box to the right to watch a report by FOX News' Megyn Kendall.

"This is a very serious investigation. And I haven't changed my mind about whether or not I'm going to comment on it publicly," he added.

The president has said he will fire any administration official found guilty of a crime in connection with the case, which is looking into whether someone in the White House violated the law by revealing the identity of Valerie Plame (search), who was a covert operative for the CIA at the time she was outed in July 2003.

Monday's events appeared to be business as usual at the White House, but tensions are said to be rising amid fears that indictments could be imminent. Without knowing special prosecutor Patrick Fitzgerald's intentions, the focus right now is on top presidential political adviser Karl Rove (search) and Vice President Dick Cheney's chief of staff, I. Lewis "Scooter" Libby (search), both of whom have been questioned before the grand jury.

Some top Republicans are saying that if indictments are issued to any White House aides, resignations should follow.

"I think they will step down if they're indicted," Sen. George Allen, R-Va., said. "I do think that's appropriate if they're in the midst of an indictment."

Fitzgerald has until Friday, when the grand jury term ends, to obtain indictments. His office launched a Web site last week that offers links to certain documents, a move some see as a way to telegraph his direction.

"It's not a good sign when what a prosecutor does, in the three days before his grand jury expires, is to create a Web site and announces the vehicle to announce something. I think people better be ready for charges," criminal defense attorney Abbe Lowell told "FOX News Sunday."

The investigation has taken nearly two years and cost over $700,000 so far. Some believe Fitzgerald, though widely described as "apolitical" and "above board," may feel pressured to produce an indictment. But those who know him maintain Fitzgerald will not pursue charges if the facts aren't there.

"He will make a responsible judgment here. And if that judgment is to walk away from this, notwithstanding the pressure, notwithstanding the money that may have been expended, I have every confidence that he will do so," said former Independent Counsel Robert Ray.

Press secretary Scott McClellan said Monday the White House is eager to learn the results of the investigation, but officials are staying "focused" on things the administration "can do something about."