(CNN) -- U.N. chief Ban Ki-moon said he "deeply regrets" a recent decision by Bahrain's highest court to uphold the verdicts against 13 activists convicted of plotting to overthrow the government.
"He reiterates his firm belief that the only way to promote peace, stability, justice and prosperity in Bahrain is through a national dialogue which addresses the legitimate aspirations of all Bahrainis, and in which all communities can participate freely, without fear or intimidation," the secretary-general's spokesman said Tuesday.
Human Rights Watch also decried the decision saying it confirms "the inability of Bahrain's judicial system to protect basic rights."
The decision Monday took just minutes. The 13 people received sentences between five years and life, said attorney Mohsin Alawi, who represents three of the 13.
The ruling by the court was the last chance the 13 had to reverse their convictions. They were arrested for their roles in anti-government demonstrations in 2011 as the Arab Spring movement swept across the region.
The Bahraini government defended the judicial procedures and decisions at the trial.
"Defendants and their lawyers were given the opportunity to present their defense through the lengthy litigation process," Salman H. AlJalahma, spokesman for the Bahraini president's office, said in a statement provided to CNN. "This process reduced one of the sentences to a quarter of their original sentence, leading to their release for time served, and the acquittal of some of the charges of two others."
The statement went on to say that "no confessions obtained through force were allowed into evidence" at the trials.
Demonstrations in Bahrain failed to gain the traction of other Arab Spring uprisings after a crackdown by authorities, backed by troops from nearby Saudi Arabia and the United Arab Emirates.
In November 2011, Bahrain's Independent Commission of Inquiry issued a report critical of authorities' reactions to the protests, which began in February 2011, spurred by uprisings in Tunisia and Egypt.
Bahrain plays a key strategic role in the Middle East and is home to the U.S. Navy's Fifth Fleet headquarters.
When Bahrain's lower appeals court upheld the convictions in September, the U.S. State Department said it was "deeply troubled" by the convictions.