European Parliament leaders have urged the EU presidency to raise the case of 26 Europeans held as terror suspects by the US in Guantanamo Bay, Cuba.
The terror suspects are being held indefinitely
MEPs called on Italian Prime Minister Silvio Berlusconi to press the US to free the suspects or put them on trial.
Mr Berlusconi avoided commenting on the issue, and it was not put to the vote.
In London, UK Prime Minister Tony Blair said a decision would be taken "soon" on the fate of Britons held at the camp which is located in a US naval base.
In Strasbourg, the head of the European Parliament's Liberal grouping, Graham Watson, lit 26 candles as he urged Mr Berlusconi - whose country currently heads the rotating presidency - to put pressure on the US.
United States Navy base in south-eastern Cuba
Leased by Washington since 1903, but not regarded as US territory
Houses more than 600 al-Qaeda and Taleban suspects
Inmates not covered by US constitutional guarantees
"The continued detention of the Guantanamo Bay 26 is unacceptable," he said.
The leader of the parliament's biggest grouping, the European People's Party, said "even the worst criminals must have the right to a fair trial".
"I am a friend of the United States but... we call on the United States to respect their human rights," said Hans-Gert Poettering.
After the debate, Mr Berlusconi told reporters that EU foreign ministers had been mandated to examine the issue of the prisoners and report back.
In July, the US agreed to suspend legal action against nine Britons being held in Guantanamo, pending discussions with British officials.
On Wednesday, Mr Blair addressed the men's legal status in a speech to the House of Commons.
"It may be that it's not possible to bring [US] rules into conformity with ours, in which case they will be returned here," he said.
The US is holding more than 600 prisoners at Guantanamo, most of whom were detained during the Afghanistan conflict that followed the 11 September 2001 attacks.
Earlier this month, the International Committee of the Red Cross described the camp as a "legal black hole".