A court in Bahrain this week said the civilian courts would retry 21 activists, including Khawaja. Sentenced to life in prison for allegedly plotting against the government, Khawaja has been on a hunger strike since Feb. 8.
Rupert Colville, a spokesman for the U.N. rights commission, said Khawaja should be given more basic privileges.
"He should be given immediate access to his family, the Danish ambassador, a doctor and a lawyer of his own choosing," he was quoted by the BBC as saying.
Khawaja holds Danish citizenship.
The BBC was granted access to the rights activist for 5 minutes in his prison cell. He vowed to continue with his hunger strike, though he's getting nutritional supplements. His wife, Khadija al-Moussawi, claims he's being fed against his will.
At least 50 people were killed during an uprising led predominately by Shiite minorities last year. The Sunni-led monarchy is said to be investigating recommendations outlined by an independent commission, though it's been criticized for its human rights record.