KYIV. Dec 26 (Interfax) - The Ukrainian Foreign Ministry has expressed strong protest against a ruling by Russia's Rostov Regional Court on December 25, 2015 to uphold a lower court ruling on extending the arrest of Ukrainian parliamentarian and pilot Nadiya Savchenko for another three months until April 16, 2016.

"Russia is continuing to ignore Nadiya Savchenko's status as a member of the Parliamentary Assembly of the Council of Europe, who enjoys immunity confirmed by PACE," the Ukrainian Foreign Ministry said in a commentary circulated on Friday evening.

"The judges' biased and politically motivated decisions are untenable," as these judges have continued to decline most of motions submitted by Savchenko's lawyers asking that evidence provided by Ukraine in a procedural way and proving that she is unrelated to the charges brought by the investigation be filed, the ministry said.

"Such actions [