The United Nations, the United States and Britain demanded during a United Nations Security Council meeting on Friday that Russia release Ukrainian military pilot Nadezhda Savchenko, but Russia defended her detention as legal.
Pro-Russia forces captured Savchenko eight months ago and handed her over to Russia, where she is being held on charges of aiding the killing of two Russian journalists in east Ukraine.
The 33-year-old, who has been on a hunger strike since December, has become a national hero in Ukraine and a symbol of resistance to Russian aggression. She denies the Russian accusation, but could be jailed for 20 years if found guilty.
"It is highly important to ensure that Ms. Savchenko is released from custody immediately. She should either be released under the "all for all" formula, or on humanitarian grounds, because of her health conditions," U.N. Assistant Secretary-General for Human Rights Ivan Simonovic told the council.
Under a deal agreed last month in Minsk, Belarus, to end fighting in eastern Ukraine, Russia and Ukraine agreed to ensure the release and exchange of all hostages and unlawfully detained people based on the principle of "all for all."
"Russia committed to releasing all prisoners, and yet Ms Savchenko and many others remain in captivity. This is a clear violation of the Minsk agreement," Britain's U.N. Ambassador Mark Lyall Grant told the council.
Russian U.N. Ambassador Vitaly Churkin said the charges against Savchenko were serious and an investigation and trial would determine her guilt or innocence.
"We keep talking about the fact that we need to protect journalists, there should be no impunity. She has been accused of this and her detention is in no way illegal," he said.
U.S. Ambassador to the United Nations, Samantha Power, described Savchenko and other Ukrainians being held in Russia as hostages. "Again, we call on Russia to release Nadezhda Savchenko," she told the Security Council.
Savchenko is accused of providing the coordinates for the attack that killed the journalists in June 2014.
She says she was detained by pro-Russian rebels an hour before the attack. Savchenko says the rebels then handed her over to Russian intelligence operatives and she was taken to Russia illegally.
Fighting between Russia-backed separatist rebels and Ukrainian government troops in eastern Ukraine has killed more than 6,000 people and more than 1 million people have been displaced, the United Nations said.
