The United States and its allies are allowing full access to captives in Afghanistan, the Red Cross said Wednesday, although the Bush administration is keeping its options open by declining to declare them prisoners of war.

"We have visited over 2,400 detainees throughout Afghanistan in over 30 places of detention," Red Cross spokeswoman Antonella Notari said a day after the first such visit to a Marines-held base near Kandahar where 16 Taliban and Al Qaeda fighters are being held. "We have no complaints about access."

Human rights watchdogs have expressed concerns that describing the captives as "detainees" instead of "prisoners of war" could impinge on rights guaranteed by international law, including the right to meet with Red Cross officials, and due process should any of them face trial.

Notari said any concerns about the captives' right to regular meetings with Red Cross officials were unfounded.

"The agreement we have with the U.S. and the U.K. and the United Front is that combatants detained are treated as POWs," she said in a telephone interview from Geneva.

Besides regular access to all captives, that means: Full, unfettered access to detention facilities; private time between the captive, the delegate and an interpreter of the Red Cross' choosing; releasing the full identity of all prisoners and allowing the Red Cross to send messages to the captive's family.

Notari said the only obstacle to regular meetings is Red Cross understaffing. The organization was recruiting native language speakers to meet the demand.

Notari refused comment on the treatment of the captives, which is standard Red Cross policy. The humanitarian group makes abuse complaints public only after all other avenues have failed.

Still, the Red Cross has confirmed that it is investigating claims that 43 Taliban captives died of suffocation on their way to Shibergan, an Afghan-controlled in prison in northern Afghanistan. Prisoners there have told reporters of severe overcrowding — 3,000 in a 200-prisoner facility — little food and medical attention, and no protection from the freezing weather.

Notari noted that Red Cross delegates have also met with American captive, John Walker Lindh, when he was held near the northern city of Mazar-e-Sharif. The Red Cross had plans to revisit him aboard the USS Peleliu, off the coast of Pakistan, where he is being held with seven other detainees.

The Pentagon says it is using "detainees" instead of "prisoners of war" because the men have not been "officially classified."

"We are treating them humanely," said Lt. Cmdr. Bruce Erickson, a spokesman for the U.S. Central Command.

Experts in military law say the Bush administration is probably avoiding the term "prisoner of war" because any captive classified that way would be entitled to a court martial, forcing prosecutors to meet tough standards.

"Court martials have very high standards of due process, greater than civilian courts," said Scott Silliman, a former Air Force lawyer who now lectures on national security at Duke University in North Carolina.

By contrast, he said, the military commissions Bush wants to use traditionally have "low standards, very low standards."

According a Nov. 13 order by Bush, this war's military commissions will block appeals and leave the decision on whom to prosecute to the president. Bush has asked Defense Secretary Donald Rumsfeld to come up with a more detailed order.

Human rights watchdogs are concerned that the commissions could bypass the right of the defendant to choose his own lawyer, to review evidence and to avoid self-incrimination.

"It's a lower standard of justice," said Amnesty International spokeswoman Vienna Colucci. "It may violate internationally recognized standards for a fair trial."

Silliman said he was reserving judgment until Rumsfeld elaborated on Bush's order, but he worried that any lower standard of justice could set a precedent for dictatorships to justify unfair trials.

"If we create this tool, it's not a tool for the United States alone to use," he said.

Another expert on military tribunals said a military commission was justified in this case.

"It's not a legitimate war, they are not legitimate fighters. They are terrorists," said Howard Levie, a retired army colonel who advised General Douglas MacArthur on the tribunals that tried Japanese war criminals.