NEW YORK, May 31 - US Ambassador to the United Nations Nikki Haley on Tuesday called on Russia to withdraw from Ukraine and acknowledge its alleged role in the 2014 downing of a commercial plane, following a recent flare-up of violence in the conflict, CNN reported.

"We condemn, in the strongest terms, Russia's involvement in eastern Ukraine and its purported annexation of Crimea," said Haley, promising US sanctions will remain in place until Russia withdraws from the long-simmering conflict, which she called "a textbook example of the direct violation of the sovereignty of one (UN) member state by another member state."

Haley made the appeal at a UN Security Council meeting on the conflict Tuesday, during which representatives were briefed on recent instability in the region.

Haley further accused Russia of creating "a catastrophe of suffering," by supporting separatist groups and violating its obligations under an international cease fire agreement.

"Despite its transparent denials," said Haley, "there is no doubt Russia is driving the Ukrainian conflict."

She also offered her support to Australia and the Netherlands, after those countries asked Russia to acknowledge its role in the downing of Malaysia Airlines Flight 17 (MH-17), which was shot down over eastern Ukraine in 2014.

An investigative team determined last week that the missile which brought down the passenger plane was fired from a launcher belonging to Russia's 53rd anti-aircraft missile brigade.

For his part, Russian Ambassador to the United Nations Vassily Nebenzia mocked "pathetic expressions" accusing Russia of aggression as "propaganda."

"We are not in a state of war with anyone," insisted Nebenzia in his characteristically impassioned remarks, which were often laced with sarcasm and peppered with heated criticism of the Ukrainian government.

He insisted that it is Kiev, not Moscow, that has undermined the cease fire and stoked the conflict.
Speaking for more than half an hour, Nebenzia dismissed Haley's criticism, noting the United States' "long history of illegally invading sovereign states."

He further questioned the investigative team's findings on the downing of MH-17, and called for a "credible" and "transparent" investigation into the tragedy. (cnn/ez)