Eight months after publicly criticising the handling of detainees at Guantanamo Bay, the head of the International Red Cross is back for talks in Washington.
The Guantanamo detentions have met worldwide protest
Jakob Kellenberger will meet Secretary of State Colin Powell and National Security Adviser Condoleezza Rice, with Guantanamo Bay again top of the agenda.
The meeting comes as military lawyers representing detainees told the US Supreme Court that the government had created a "legal black hole".
They urged civilian appeals be allowed.
"The government's argument in this case has no logical stopping-point," they said in a "friend-of-the-court" brief.
"If there is no right to civilian review, the government is free to conduct sham trials and condemn to death those who do nothing more than pray to Allah."
They said the open-ended process was something "the constitution cannot countenance".
The five lawyers were assigned to defend some of the 660 detainees at Guantanamo Bay.
They do not challenge the president's right to hold those captured in the so-called "war on terror".
They do, however, argue detainees should not be tried, convicted and sentenced - possibly to death - in military courts without the right to appeal in civilian courts.
Mr Kellenberger is likely to press a similar point when he meets Mr Powell, Ms Rice and Deputy Defence Secretary Paul Wolfowitz during his two-day visit to Washington.
Mr Kellenberger wants the legal status of detainees to be addressed
Last May, he unusually spoke out to demand that the trials of detainees follow due legal process and that their status be defined.
He will now want to know why no progress has been made, says the BBC's Imogen Foulkes.
At the moment, the US Government classes detainees as "enemy combatants" and says they can be held indefinitely without charge.
The International Red Cross is one of the only groups allowed regular access to those held.
On Wednesday, a Los Angeles lawyer filed a $1.1bn class action case on behalf of the Guantanamo detainees.
It followed last month's ruling by the 9th US Circuit Court of Appeals that courts could hear petitions from detainees.
The suit filed by Stephen Yagman claims that ruling shows detainees are US "inhabitants" and can thus sue for breaches of their constitutional rights - including freedom of speech, association and religion.
The suit also claims there is no legal basis for the detention of those at Guantanamo Bay.