The government disclosed the figures for 1997 and 1998 - $26.6 billion and $26.7 billion, respectively - but has balked at having to do so again.
President Clinton said in 1996 that the total spending level should be public information.
But Justice Department lawyer Andrea Cohen said Monday that CIA Director George Tenet had convinced the president there should be no further disclosure of the figure and Tenet's judgment "should carry the day.''
"The world is very different today than what it was in 1997,'' Cohen argued at a hearing before U.S. District Judge Thomas Hogan.
Hogan promised a ruling on a Justice Department bid to block a lawsuit seeking the overall intelligence budget number for fiscal 1999. He did not say when he would make it.
Kate Martin, a lawyer for the Federation of American Scientists, which brought the suit, told Hogan that little could be gleaned from the total spending figure "other than how U.S. tax dollars are being spent.''
Steven Aftergood, senior research analyst for the federation, told The Associated Press that his organization estimates the intelligence budget increased sharply in 1999, to about $29 billion.
Cohen, the Justice Department attorney, said having specific information on changes in spending levels could reveal much to a sophisticated adversary.
The intelligence budget, sometimes called "black'' spending by Congress, is scattered and fragmented through dozens of defense and other programs in the federal budget to hide them from public scrutiny.
The Federation of American Scientists went to court to obtain the figures after the administration denied a Freedom of Information Act request seeking the spending figure - on national security grounds.