The Lithuanian parliament on Thursday called for the criminal prosecution of Russia's leadership for its invasion of Ukraine and what it said is the wide-scale forced deportation of Ukrainians to Russian territory.

At least a million Ukrainians were deported to Russia and Russian-controlled territories, including 200,000 children, the parliament said in a motion that was passed unanimously.

Moscow calls its nearly three-month-old invasion a "special military operation" to rid Ukraine of fascists, an assertion Kyiv and its Western allies say is a baseless pretext for an unprovoked war.

"Justice will only be achieved through the prosecution of Russian leaders, other high-ranking organizers of the crimes, and direct perpetrators of the hostilities and the civilian deportations in Ukraine", the motion said.

The motion does not name a specific authority that should carry out the prosecution, but calls on "other countries" to make use of the principle of universal jurisdiction that allows countries to try accused war criminals from other nations.

Prosecutors investigating war crimes cases in Ukraine are examining allegations of the forcible deportation of children to Russia since the invasion as they seek to build a genocide indictment, Ukraine's top prosecutor said on June 3.

Russia's TASS state news agency on May 30 quoted an unnamed law enforcement official as saying that "more than 1.55 million people who arrived from the territory of Ukraine and Donbas have crossed the border with the Russian Federation. Among them, more than 254,000 children."

The parliaments of Lithuania and the other Baltic countries of Latvia and Estonia have passed motions labelling Russian actions in Ukraine a "genocide", with Lithuania adding that its actions also constitute "terrorism".

The Lithuanian motion was passed on the anniversary of the start of a programme of mass deportations of Lithuanians to Siberia in 1940 after the country was forcibly incorporated into the Soviet Union.

About 130,000 people were exiled during the next decade and a half, the parliament said.