Ukrainian pilot Nadiya Savchenko, the most famous prisoner of the Ukraine conflict, loudly sang to the judge Tuesday while being sentenced to 22 years in Russian prison for murder.
"Oh judge, what are you judging me for?" she sang to the tune of the traditional Slavic folk song Oh Braids of Mine, a video from the courtroom posted on YouTube showed.
The judge called for order and waited for Savchenko to calm down before declaring the final portion of the verdict as Savchenko wore a sardonic smile.
The 34-year-old was accused of giving Ukrainian national forces the coordinates for an attack in which two Russian journalists were killed.
She was found guilty of murder, attempted murder and illegally crossing the Russian border during the conflict over Ukraine's two eastern-most regions, Russian state news agency TASS reported.
The court, in the southern Russian town of Donetsk near the Ukrainian border, said Savchenko's prison term includes the nearly two years that she has been in Russian custody.
Ukrainian President Petro Poroshenko called for Russia to return Savchenko to his country in exchange for two Russians captured by Ukrainian forces.
He described the two Russians as military servicemen detained "for their participation in armed aggression against Ukraine," according to a statement on his website.
It took the judge more than 14 hours - two full days of court proceedings - to read the entire text of the verdict, which included detailed descriptions of Savchenko's crime and interactions with alleged accomplices.
Savchenko's legal team said the text apparently consisted of hundreds of pages.
After Savchenko was taken into Russian custody in mid-2014, Ukraine appointed her as a member of its delegation to the Parliamentary Assembly of the Council of Europe, giving her diplomatic immunity.
However, the Russian prosecutor argued that the immunity is not applicable to the case because the appointment was made after the alleged crime.
The United States on Tuesday condemned the conviction and sentence, saying it showed "a blatant disregard for the principles of justice" and was contrary to Russia's commitments under the Minsk agreement.
"For nearly two years, Russia has unjustly detained Savchenko on charges that have no basis in fact and has denied her the basic protections of the rule of law," State Department spokesman John Kirby said, calling for her to be returned to Ukraine and for other unlawfully detained prisoners to be released.
In New York, Volodymyr Yelchenko, Ukrainian ambassador to the United Nations, said he was meeting with UN officials and members of the UN Security Council to demand "any possible actions on their side."
In early 2014, a pro-Russian separatist rebellion erupted in eastern Ukraine after the country ousted its pro-Russian president amid mass protests calling for closer ties with the West and after Russia occupied and annexed Crimea.
More than 9,000 people have died in the conflict between the separatists and the Ukrainian military, according to estimates by the UN.
Kiev and many Western powers accuse Moscow of fuelling the conflict with supplies of weapons and troops for the separatists. Moscow has adamantly denied such claims.