BELFAST, Northern Ireland -- Northern Ireland's Catholic-Protestant administration won't be revived unless the Irish Republican Army disbands, leading British and U.S. officials predicted Tuesday.

IRA commanders remained silent about Britain's resumption of authority in Northern Ireland after nearly three years of local power-sharing between two British Protestant parties and two Irish Catholic parties, including the IRA's Sinn Fein.

Most politicians and commentators blamed the political breakdown on the IRA. Police have accused the outlawed group of pursuing a range of violent and duplicitous activities, including spying on Sinn Fein's coalition partners.

"There can't be any tolerance for this sort of behavior," said Richard Haass, President Bush's point man on Northern Ireland affairs, who called on the IRA "to go out of business."

"The IRA needs to give up all of its paramilitary dimension. It needs to give up any acts of violence.

"It needs to give up preparations for acts of violence. It needs to give up its arms," said Haass, director of policy planning at the State Department.

If this didn't happen, he said, "I don't see how you're going to build the required level of trust that has to be in place in order for power-sharing, in order for devolved governance, to resume."

In London, Britain's governor for the province, Northern Ireland Secretary John Reid told lawmakers Sinn Fein was still "riding the two horses" of politics and violence.

He said Protestants would not trust Sinn Fein unless the IRA declared its violence was "a thing of the past" and ceased all activities.