A White House official indicated Tuesday that relatives of three dead Brothers to the Rescue members will not be able to tap frozen Cuban assets to collect on a multimillion-dollar judgment against Fidel Castro's government.

With lawyers standing at their side, relatives complained at a Miami news conference that President Clinton had ``reneged'' on a promise he made in 1996 to ensure they would be compensated from a pool of ``blocked'' Cuban assets.

Last week, Clinton invalidated a provision of the Treasury and General Appropriations Act of 1999 that would have allowed the relatives to pursue the assets and collect on a $187.6 million judgment they won against Castro's government and air force.

After four Brothers members died in the 1996 shootdown, Congress passed a law allowing the victims of terrorism to file suits against nations alleged to have sponsored acts of violence that caused injury or death. This year's appropriations bill was even more specific: It allowed victims to pursue a nation's assets frozen by the United States. The frozen Cuban assets, according to government estimates, total more than $170 million.

But Clinton voided the provision on national security grounds. Seizing on language in the measure, Clinton invalidated it.

Attorneys for the Brothers victims' families say the president improperly broadened the grounds for a waiver.

``This law provided for justice for victims of terrorism,'' said Miami attorney Aaron Podhurst, one of the lawyers representing families of Carlos Costa, Armando Alejandre and Mario de la Pena. ``Unbelievably, the president issued an order attempting to nullify the entire law.''

The fourth victim, Pablo Morales, could not join the legal action because he was not an American citizen.

The White House official suggested that as far as the administration is concerned, the families already have been compensated. He pointed to $1.2 million in humanitarian aid authorized by the president in 1996.

``We deeply sympathize with the families of the shootdown victims,'' said the official, who declined to be identified by name. ``The United States government took strong steps against Cuba and marshaled forceful international condemnation of it.

``There is also the broader consideration that putting these families at the head of the line potentially disadvantages thousands of certified claimants who have waited for compensation,'' he added. ``What the court awarded the families surpasses the value of the Cuban assets. We have tried to present the right balance.''