WASHINGTON - The Cuban government is ''impeding our efforts to defeat terrorism'' by feeding U.S. officials misleading information ''fabricated by Castro's intelligence apparatus,'' a Bush administration official charged Tuesday.

''This is not harmless game-playing -- it is a dangerous and unjustifiable action that damages our ability to assess real threats,'' said Dan Fisk, deputy assistant secretary of state for the Western Hemisphere. ``It could one day cost innocent people their lives.''

In speeches to two groups on opposite sides of the debate over U.S.-Cuba issues, Fisk said that beginning on the day of the attacks, Sept. 11, Cuban agents gave U.S. officials ``false leads seeking to misdirect the investigation.''

''This was only the beginning of a steady stream of what has turned out to be wild goose chases intentionally initiated by the Castro regime,'' Fisk said in his speeches.

In an interview later, Fisk told The Herald: ``We've seen instances on three continents. . . . The responsible agencies found a discernible pattern of information that leads us to conclude that this is part of a continuing pattern of false leads.''

He declined to provide details about the persons and information involved, saying only that the ''responsible agencies'' had determined the people were ''Cuban agents.'' Fisk said his words were ''chosen carefully'' and were cleared by intelligence and law enforcement agencies.

At least once a month Cuban representatives have tried to ''set up our intelligence and law enforcement'' with false tips that took time to check out, Fisk said.

The Cuban Interests Section in Washington did not respond to phone calls about Fisk's allegations.

Over the years, any contacts between U.S. and Cuban officials have been fraught with intrigue and distrust.

A top Bush administration official told The Herald soon after the Sept. 11 attacks that Cuba had provided ''no significant or new information'' about possible terrorist activity. U.S. intelligence officials who have dealt with the Cubans on several cases involving Miami-based Cuban exile terrorism plans have complained that when they asked for evidence on alleged plots, the Cubans turned over reams of papers that amounted to little more than newspaper clippings, and unsourced ''reports'' full of rhetoric but thin on hard facts.

But a senior U.S. intelligence official said last month that in fact the Bush administration had been reluctant to accept counterterrorism information from Cuba right after the Sept. 11 attacks because it did not want to be seen as cooperating too closely with the communist-ruled island.

RAISING THE BAR

Bush administration officials ''raised the bar'' on what would constitute ''real cooperation'' from Cuba to make sure that the Castro government would not meet those requirements, the official added on condition of anonymity.

Miami's two Cuban-American House members said Tuesday they were told that some of the alleged disinformation, described as tips about pending attacks, came from Cuban officials and agents overseas.

''This is much worse than a lack of cooperation,'' said Rep. Lincoln Díaz-Balart, a Miami Republican. ''The Castro regime is purposefully directing a campaign of disinformation to hamper the U.S. war on terrorism.'' Rep. Ileana Ros-Lehtinen, also a Republican, said ``the Cuban intelligence apparatus knows what's a real lead and what's not -- they know good information from a red herring.''

After the Sept. 11 attacks, U.S. officials appealed globally for help in tracking and capturing al Qaeda terrorists.

Traditionally unfriendly governments, including Syria and Sudan, provided helpful information, U.S. officials said.

Fisk, a former aide to Sen. Jesse Helms, R-N.C., said Cuba promised to help, but instead ``actively and intentionally worked through human and electronic means to distract attention and resources from our ongoing counter-terror efforts.''

The Senate Intelligence Committee received a preview of Fisk's comments, a spokesman said. Chairman Bob Graham, a Florida Democrat, was briefed on Iraq and was preparing for today's initial public hearing on the Sept. 11 probe and was not briefed on Cuba.

TWO GATHERINGS

Fisk spoke to two gatherings that brought hundreds of advocates, for and against the U.S. embargo, to the National Press Club in Washington. He gave a broad defense of the administration's hard-line approach to Cuba.

He received a warm reception from Americans for a Free Cuba, which supports Bush policy, when he said ending the embargo ``would benefit the Castro regime at the expense of the Cuban people.''

Anti-embargo advocates, holding a ''National Summit on Cuba,'' sharply questioned Fisk about U.S. dealings with China, Saudi Arabia and Pakistan despite human rights abuses there, while Cuba was singled out for isolation.