Washington ? President-elect Obama’s advisers are crafting plans to close the Guantanamo Bay prison and prosecute terrorism suspects in the U.S., a plan the Bush administration said Monday was easier said than done.

Under the plan being crafted inside Obama’s camp, some detainees would be released and others would be charged in U.S. courts, where they would receive constitutional rights and open trials. But, underscoring the difficult decisions Obama must make to fulfill his pledge of shutting down Guantanamo, the plan could require the creation of a new legal system to handle the classified information inherent in some of the most sensitive cases.

Many of the about 250 Guantanamo detainees are cleared for release, but the Bush administration has not been able to find a country willing to take them.

Advisers participating directly in the planning spoke on condition of anonymity because the plans aren’t final.

The plan being developed by Obama’s team has been championed by legal scholars from both political parties. But as details surfaced Monday, it drew criticism from Democrats who oppose creating a new legal system and from Republicans who oppose bringing terrorism suspects to the U.S. mainland.

Obama foreign policy adviser Denis McDonough said the president-elect wants Guantanamo closed, but no decision has been made “about how and where to try the detainees, and there is no process in place to make that decision until his national security and legal teams are assembled.”

Obama seeks a break from the Bush administration, which established military tribunals to prosecute detainees at the Navy base in Cuba and strongly opposes bringing prisoners to the United States. At the White House, spokeswoman Dana Perino said Monday that President Bush has faced many challenges in trying to close the prison.

“We’ve tried very hard to explain to people how complicated it is. When you pick up people off the battlefield that have a terrorist background, it’s not just so easy to let them go,” Perino said. “These issues are complicated, and we have put forward a process that we think would work in order to put them on trial through military tribunals.”

But Obama has been critical of that process and his legal advisers said finding an alternative will be a top priority. One of those advisers, Harvard law professor Laurence Tribe, acknowledges that bringing detainees to the U.S. would be controversial but said it could be accomplished.

“I think the answer is going to be, they can be as securely guarded on U.S. soil as anywhere else,” Tribe said. “We can’t put people in a dungeon forever without processing whether they deserve to be there.”

The tougher challenge will be allaying fears by Democrats who believe the Bush administration’s military commissions were a farce and dislike the idea of giving detainees anything less than the full constitutional rights normally enjoyed by everyone on U.S. soil.