In a statement, Frank Lindh and Marilyn Walker said they're growing impatient because the Red Cross told them it has been unable to deliver their Dec. 4 letter of support.
"It is very painful to think that John has no idea his family is sending him love and support during the most difficult time of his life," Lindh's parents said in a statement released by their attorney.
Dominick Albano, a spokesman for the local Red Cross, said late Tuesday its office in Pakistan has the family's letter and it's not unusual for such a delivery to take up to three months. Lindh's unique status further complicates matters.
"This situation with the Walkers is completely unprecedented," Albano said. "It's a murky area. We're working closely with all parties involved and we're certainly committed to helping the family."
Albano said the family's letters were personal, not political.
"They're 'Are you okay? Are you eating? Are you getting proper medical attention,'" he said.
A spokesman for the U.S. war effort had no immediate comment on the letter, and questioned how the family knew it had not been delivered.
Earlier in the day, Deputy Secretary of Defense Paul Wolfowitz said Lndh is "being treated consistent with the Geneva protections for prisoners of war."
Under those rules, prisoners of war are allowed to send and receive letters and cards, which must be conveyed rapidly and cannot be withheld "for disciplinary reasons." Wolfowitz added, however, that because Lindh "is not a legal combatant ... he's not legally a prisoner of war."
Lindh, of San Anselmo, Calif., was found holed up with Taliban fighters after northern alliance forces brought an end to a prison uprising near the northern Afghan city of Mazar-e-Sharif more than two weeks ago.
Lindh had been held as a prisoner in a detention center at Camp Rhino, the U.S. Marine base in southern Afghanistan. Late last week, he was flown to the USS Peleliu, the lead ship of a military unit off the coast of Pakistan.
The government has not yet determined whether Lindh's case falls under the jurisdiction of military or civilian justice.
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