Fitzgerald declined to comment as he emerged from the federal courthouse after the grand jury adjourned for the day on Wednesday without announcing any indictments.
Fitzgerald met separately for 45 minutes in the chambers of the chief US District Judge Thomas Hogan, who oversees the grand jury. Fitzgerald and Hogan meet regularly to discuss the status of the leak case.
An announcement on indictments could come on Thursday or Friday, when the panel is scheduled to meet again for the last time. The grand jury is set to expire on Friday, but Hogan could in secret extend its life at Fitzgerald's request.
The grand jury meeting followed a last-minute flurry of interviews by investigators with outed CIA operative Valerie Plame's neighbours and a former colleague of top White House adviser Karl Rove.
Plame's identity was leaked to the media after her diplomat husband, Joseph Wilson, accused the administration of twisting prewar intelligence on Iraq. Wilson said it was done deliberately to erode his credibility.
White House adviser Karl Rove is
at the centre of the investigation
Fitzgerald's investigation has centred on Lewis Libby, chief of staff for Vice President Dick Cheney, and Rove, President George Bush's top political adviser, and their conversations with reporters in June and July 2003 about Wilson and his wife.
Other former and current White House aides may be charged, lawyers involved with the case said.
Any charges brought by the grand jury could be sealed, preventing an immediate public announcement by the court or the prosecutor.
A USA TODAY/CNN/Gallup poll found the investigation was affecting Americans' view of the White House, with almost four in 10 respondents saying they think Bush aides broke the law. Another four in 10 said administration officials had acted unethically.
White House officials were anxiously awaiting the outcome of the case because any indicted officials were expected to resign immediately.
Rove and Libby were at the White House senior staff meeting in the morning as usual, an official said. White House spokesman Scott McClellan would not say whether the leak subject came up in the meeting.
"We certainly are following developments in the news, but everybody's got a lot of work to do," he said.
Mission to Africa
Wilson based his criticism partly on a CIA-sponsored mission he made to Africa in 2002 to check an intelligence report that Iraq sought uranium from Niger. Bush cited that report in his 2003 State of the Union address, but Wilson later said the claim was unsubstantiated.
Fitzgerald has asked witnesses about the Niger report, which has been traced in part to Italy's intelligence service, known as Sismi, US officials say. The chief of Sismi, Nicolo Pollari, met with Stephen Hadley, the then-deputy White House national security adviser, on 9 September 2002.
The White House confirmed the meeting on Wednesday but would not say whether the Niger report was discussed.
Lawyers involved in the case said it could be difficult for Fitzgerald to charge administration officials with knowingly revealing Plame's identity.
They said Fitzgerald appeared more likely to seek charges for easier-to-prove crimes such as making false statements, obstruction of justice and disclosing classified information.
But there were 11th-hour signs that Fitzgerald could bring charges for the leak itself.
FBI agents on Monday night questioned some of Plame's neighbours about whether they knew about her CIA work before her identity was leaked to the media. The interviews could help Fitzgerald show that Plame's status had been a closely guarded secret.