Russia's parliament approved the annexation of Crimea on March 21 last year after Russian forces took control of the peninsula, which is home to Russia's Black Sea Fleet, and residents backed joining the Russian Federation in a referendum.
"We consider this event counterproductive and provocative. It doesn't fall within the purview of the U.N. Security Council," Russian U.N. mission spokesman Alexey Zaytsev said.
A deadlocked 15-member Security Council has held more than 30 meetings on Ukraine since the seizure of Crimea. Fighting between Russia-backed separatist rebels and Ukrainian government troops in eastern Ukraine has killed more than 6,000 people and displaced more than 1 million people, the United Nations says.
Lithuania's U.N. Ambassador Raimonda Murmokaite, who organized the informal meeting, said it was unfortunate that Russia, China, Venezuela and Angola had not attended.
"Russia is normally very quick to criticize Ukraine on alleged human rights violations, but completely ignores human rights violations happening under its own rule or under its proxy's rule," she told reporters.