U.S. and coalition forces in Afghanistan are holding about 7,000 Taliban and Al Qaeda prisoners and slowly screening them in an effort to weed out the leaders who may deserve prosecution outside the country, U.S. officials said Friday.

In the first accounting of the total number of detainees, U.S. officials said they are being guarded by anti-Taliban fighters as well as U.S forces in places like the Marine base at Kandahar airport, where a detention camp has been hastily constructed in recent days.

Kenton Keith, a former U.S. ambassador to Qatar, said the process of screening the detainees is taking considerable time but could yield important information about Usama Bin Laden's terror network.

"It is essential to find out who was who within the Al Qaeda network. To separate those who were the executives, the ones that gave orders, the sympathizers, the late-joiners, and the true believers, but without executive powers," Keith said.

But coalition forces still don't have a fix on their primary target: bin Laden.

"I don’t know where he is. I'd rather not speculate if he's alive," Gen. Richard Myers, Chairman of the Joint Chiefs of Staff said. "We're following up on all leads. If he's left Afghanistan, fine. In the end, I'm confident we will find him."

Myers spoke at a secret airbase in the region, a base humming with cargo planes, heavy lift transport and attack helicopters, unmanned reconnaissance Predator aircraft and hundreds of Air Force, Army Rangers, Navy and Marine aviators as well as coalition forces. For security reasons, the Defense Department asked that the location not be reported.

The general urged Americans to be patient, saying there's no timetable for finding bin Laden or other senior Al Qaeda and Taliban leaders. "This is a long struggle. It's event-driven, not timetable driven," Myers said. "Everybody seems to think it's over. I don't think it's over. We know who we want. We have to figure out where they are."

The Associated Press contributed to this report.