SAN JUAN, Puerto Rico - Rather than shutting Guantanamo, the U.S. military is gearing up for the war-crimes trial of a former child soldier at the navy base on southeastern Cuba this summer.

The case of detainee Omar Khadr highlights how President 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 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 attorneys.

Court proceedings against Khadr, who is accused of killing a U.S. soldier in Afghanistan, are farthest along. But pretrial hearings are anticipated for several other detainees at Guantanamo in 2010.

Obama's order to close the prison by Jan. 22, 2010, was a symbolic break from Bush administration antiterrorism policies, which Obama said cost the United States its stature around the world. But Obama has had trouble lining up help from other countries and even his own party.

Meanwhile, he has directed the government to acquire and upgrade the Thomson Correctional Center, in rural western Illinois, for some detainees. It is 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.

"The military can do some great things, but I don't see that happening before July," Jackson said.

Human-rights advocates said more trials at Guantanamo would revive international criticism.

Guantanamo "symbolizes a lack of lawfulness and human-rights violations over the last seven years," said Jamil Dakwar, a lawyer with the American Civil Liberties Union.

Joseph DellaVedova, a spokesman for the Pentagon's Office of Military Commissions, said prosecutors were continuing to prepare cases that would go before military commissions "regardless of a trial location."