The US Supreme Court has rejected an appeal by two Chinese Muslims who are seeking release from the US detention centre at Guantanamo Bay, in Cuba.
The Uighurs appear to have nowhere to go
The judges declined to hear their case because the men are due to have a hearing in a lower court next month.
A US federal judge has already said their detention is unlawful, but ruled that he could not order their release.
The pair - both ethnic Uighurs - were mistakenly captured as enemy combatants in Pakistan more than four years ago.
'Unable to return'
The US military determined a year ago that Abu Bakker Qassim and A'del Abdu al-Hakim were not "enemy combatants" as had been thought when they were captured in Pakistan in 2001.
However, the Bush administration says it cannot return the Uighurs to China because they would face persecution there.
It does not want to admit them to the US, and cannot find another country to take them.
Ethnically Turkic Muslims, mainly in Xinjiang
Made bid for independent state in 1940s
Sporadic violence in Xinjiang since 1991
Uighurs worried about Chinese immigration and erosion of traditional culture
Beijing has frequently cracked down on Uighur dissidents, who are seeking autonomy in the country's north-western Xinjiang province.
The Chinese government accuses Uighur militants of waging a bombing and assassination campaign, and receiving training at al-Qaeda camps in Afghanistan.
The two men have been held at Guantanamo since June 2002. The detention centre has about 490 inmates, 15 of whom are believed to be Chinese Uighurs.
Their case could return to the Supreme Court after the lower court hearing.
Chinese President Hu Jintao is due to arrive in the US on Tuesday and will hold talks with US President George W Bush on Thursday.
Correspondents say the Uighur problem at Guantanamo Bay is illustrative of the complex issues facing the two leaders, but that it is unlikely either side will raise the subject at their meeting.