The UN torture investigator has accused the United States of stalling on his requests to visit several prisons across the country to probe the use of solitary confinement and to interview inmates at the US military prison at Guantanamo Bay in Cuba on his terms.

Juan Mendez, special rapporteur on torture, harshly criticised Washington on Wednesday for not providing him with "acceptable" access to the Guantanamo facility and to the 122 detainees still being held there.

The US, Mendez said, had invited him to visit the prison camp in 2012, but under "unacceptable" conditions.

He said he would be allowed to only visit parts of the prison, adding that the conditions precluded him from having “any unmonitored or even monitored conversations with any inmate in Guantanamo Bay”.

Mendez also lamented that for over two years, he has sought to enter federal prisons in New York and Colorado as well as state prisons in California and Louisiana, among others, to check on conditions there to no avail.

Mendez said he was particularly concerned about the use of solitary confinement, or the practice of isolating an inmate from others, for underage offenders.

Solitary confinement for children "should never happen, even for a single day," he said, pointing out that the punishment, widely considered cruel even for adults, was "particularly harmful for children because of their state of development and their special needs".

According to the American Civil Liberties Union (ACLU), an advocacy group, more than 80,000 people are held in solitary confinement in the US on any given day.

Mendez said the US State Department had been working to help him gain access to the state prisons, but after two years of discussions he had yet to receive a positive answer, much to the disappointment of activists.

"It's simply outrageous that it's taking such a long time to provide access to American detention facilities," said Jamil Dakwar, head of human rights at the ACLU. "This begs the question: is the United States hiding something?" he wrote in an email to the AFP news agency.

Source: Agencies