Russian Federation Ambassador Vitaly Churkin. Picture: Richard Drew

United Nations, United - Russia warned Ukraine Friday of “catastrophic consequences” unless it halted a military operation against pro-Russian gunmen, while Western powers rounded on Moscow at emergency United Nations talks.

Russia called the Security Council meeting on Ukraine, the 13th since the crisis began, after pro-Russian rebels shot down Ukrainian helicopters and the Kremlin said a peace deal was dead.

Ukraine and its Western allies accuse Russia of fomenting the rebellion and Kiev launched a military operation to seize back control of the flashpoint town of Slavyansk, in Ukraine's increasingly volatile east.

Seven people were killed in the town on Friday, including two Ukrainian military personnel shot down in two helicopters.

“If the criminal misadventures of Kiev are not swiftly stopped then catastrophic consequences for Ukraine cannot be avoided,” Russian ambassador Vitaly Churkin told the 15-member Council.

He rounded on Kiev and its Western allies, accusing the United States of “blatant” double standards and claiming that English-speaking foreigners were interfering on the ground in Ukraine.

Demanding a halt to “all punitive operations,” Churkin said: “It is time for Western colleagues to think twice.”

UN Secretary General Ban Ki-moon reiterated grave concern and called for maximum restraint to avoid more bloodshed, saying that a diplomatic solution was the only way out of the mounting crisis.

“Escalating violence and reported further loss of life in the city of Slavyansk today is a stark reminder of how dangerous the situation has become,” he said in a statement.

Western powers, facing the biggest test of relations with Moscow since the Cold War, expressed full support for Ukraine's military operation.

The United States said Russian-directed agents and paramilitaries were responsible for “horrible violence” and accused Russia of trying to “replicate the charade” that led to its annexation of Crimea in March.

Russian expressions of concern were “cynical and disingenuous,” said US ambassador Samantha Power.

Ukraine's response is “reasonable, it is proportional and it is frankly what any one of our countries would have done,” she said.

British ambassador Mark Lyall Grant called on Russia “to step back from such rhetoric, to desist from their inflammatory propaganda and commit to de-escalating a perilous situation.”

“There is no council member sitting at this table that would allow its towns to be overrun by armed militants,” he said.

“The scale of Russian hypocrisy is breathtaking,” he added, accusing Moscow of arming the most repressive regimes in the world, including close ally Syria.

He said “peaceful activists” as claimed by Russia do not have the means to shoot down helicopters.

“Sophisticated weaponry against Ukrainian forces reaffirms our assessment that the armed groups include professionals funded and equipped by Russia,” Grant said.

Russia has consistently denied it has anything to do with the armed groups.

Ukraine's deputy ambassador, Oleksandr Pavlichenko, refused to shoulder any responsibility for the crisis on Friday, calling on militants to lay down their arms and vacate public buildings.

“Russia strongly supports illegal militant groups operating in the eastern region of Ukraine, endangering civilians, seizing hostages and creating an atmosphere of terror and violence,” he said.

“We will ensure peace and stability, and stop the terrorist threat in the east of Ukraine.”