Rather than shutting Guantanamo, the U.S. military is gearing up for the war-crimes trial of detainee Omar Khadr at the navy base on southeastern Cuba this summer.

Khadr's case highlights how President Barack Obama has struggled to carry out a pledge he made immediately after taking office to close the globally unpopular military prison, which he called a recruiting tool for terrorists.

But if some trials are to proceed without delay, there is no other viable location, thanks to Congressional opposition to moving terror detainees to U.S. soil, plus the time required to buy and renovate an Illinois prison — the one place where they would be welcome.

"The prosecutors in Khadr's case have informed us that if the trial takes place in July 2010, it will be held at Guantanamo," said Army Maj. Jon Jackson, one of the detainee's Pentagon-appointed lawyers.

Court proceedings against Canadian-born Khadr, who is accused of killing an American soldier in Afghanistan, are farthest along. But pretrial hearings are anticipated for several other detainees at Guantanamo this year.

Obama's order just two days into his presidency to close the prison by Jan. 22, 2010, was a symbolic break from Bush administration anti-terrorism policies, which Obama said cost the U.S. its stature around the world.

But the president has had trouble lining up help from other countries and even his own political party. Republicans and some Democrats have vehemently opposed moving terror suspects to U.S. soil, citing security fears.

About 50 detainees have been transferred to other countries under Obama. But the administration is still trying to reach a repatriation agreement with Yemen, a country that accounts for nearly half the remaining 198 detainees.

Meanwhile, the president has directed the government to acquire and upgrade the Thomson Correctional Center, a maximum-security facility in rural western Illinois, for some detainees. But it's not clear if Congress will approve the funds. Even if it does, authorities say it would take up to 10 months to upgrade security and add a courtroom there.

Human rights advocates said more trials at Guantanamo would revive international criticism of the U.S. Khadr is one of five inmates facing charges in the military courts, known as commissions, that were launched under the Bush administration following the Sept. 11, 2001, terrorist attacks.

The commissions were widely criticized because they denied defendants most of the rights they would be granted in a civilian court or even in a traditional military court martial. But the Obama administration recently revised the system to expand legal protections for defendants.

The Toronto-born son of an alleged al-Qaeda financier, Khadr was captured when he was 15 and accused of throwing a grenade that killed U.S. Army Sgt. 1st Class Christopher Speer of Albuquerque, N.M., during a 2002 battle in Afghanistan.

As with many of the remaining detainees at Guantanamo, the U.S. has limited options for Khadr. Prime Minister Stephen Harper has refused to request his return, despite pressure from courts and opposition parties to do so because of his young age.

Khadr also has maintained that his statements to interrogators were obtained through abuse, an argument that could carry more weight in civilian U.S. courts that bar evidence obtained under coercion.