Ukrainian lawmaker Nadia Savchenko has announced the formation of a new movement after a split with her former political party.

Savchenko, an ex-military aviator who spent nearly two years in Russian jails, announced in the western city of Lviv on December 27 that she had established the Civic Platform RUNA, an acronym for Ukrainian People's Revolution.

Savchenko said RUNA will not be a "political project" but rather a "mechanism" that she described as a "natural association of people" who do not follow "populist slogans."

Savchenko, 35, quit the Batkivschyna (Fatherland) party headed by former Prime Minister Yulia Tymoshenko in October and was formally expelled from it earlier this month.

The party was critical of Savchenko's meeting in Minsk with Russia-backed separatist leaders from eastern Ukraine to discuss a prisoner swap.

On December 22, Savchenko was expelled from Ukraine's delegation to the Parliamentary Assembly of the Council of Europe (PACE) and later from the Parliamentary Committee for National Defense and Security.

Savchenko says she was abducted by Russia-backed separatists in eastern Ukraine in June 2014 and taken illegally into Russia, where she was jailed and tried on charges of involvement in what Moscow called the killing of two Russian journalists who died in the conflict between the separatists and Kyiv's forces.

Savchenko was convicted earlier this year and sentenced to 22 years in prison, but was pardoned by Russian President Vladimir Putin on May 25 and released in a swap for two Russians held by Kyiv, which said they were servicemen. She was widely hailed as a hero upon her return to Ukraine, but has faced criticism from nationalists since then.

Meanwhile, pro-Moscow separatists released two women captives on December 27.

The women -- judge Anzhelika Presnyakova and journalist Olha Svorak -- were reportedly released due to Savchenko's efforts.

With reporting by AFP, the Kyiv Post, and TASS