Russia came under heavy criticism from world powers at an emergency meeting of the United Nations Security Council Sunday, as violent clashes flared between pro-Russia separatists and Kyiv government supporters in eastern Ukraine.
U.S. Ambassador Samantha Power and British Ambassador Mark Lyall Grant accused Russia of orchestrating the violence.
Power said the instability in Ukraine was "completely man-made." She said it was "written and choreographed" by Russia. Grant called on the Security Council to warn Russia against "further military escalation."
Russia, which called the meeting, rejected the charges.
Russian Ambassador Vitaly Churkin called on the international community to demand that those who are in power in Kyiv stop war on their own citizens, referring to a warning by Ukraine’s government that it will use force against pro-Russia activists in the eastern part of Ukraine if they do not disarm.
In a televised speech Sunday, Ukraine's acting president, Oleksandr Turchynov, vowed Kyiv will not let Russia take over eastern Ukraine after its annexation of the Crimean peninsula last month.
He said he will grant amnesty to any pro-Russian separatists who lay down their weapons by Monday but vowed to use force against those who don't.
Turchynov accused Moscow of carrying out a war against Ukraine, once part of its Soviet empire.
"Blood has been shed in a war which the Russian Federation unleashed against Ukraine. The aggressor has not stopped but continues to incite unrest in Ukraine’s east. It's not a war between Ukrainians; it's an artificially created confrontation, whose goal is to see Ukraine weakened and destroyed as a country. But in the end it will weaken our enemies. Russia today has drawn condemnation from the entire civilized world,'' said Turchynov.
Russia’s Foreign Ministry immediately dismissed Turchynov’s order to launch the operation as "criminal" and called for its immediate review by the U.N. Security Council. A meeting is set for Sunday night.
Turchynov's speech came hours after Ukrainian special forces and pro-Russian militia exchanged gunfire in the eastern Ukrainian city of Slovyansk, with both sides reporting casualties.
Ukraine's interior minister, Arsen Avakov, said a security service officer was killed and another five wounded in the latest skirmish in the aftermath of Moscow's Crimea take-over last month. At least one pro-Russian activist was also reported killed in the gunfire and two injured.
Russia draws condemnation
The escalation came a day after pro-Russian gunmen took over the Slovyansk police station, and government facilities in the largely Russian-speaking cities of Donetsk and Kramatorsk.
U.S. ambassador to the U.N., Samantha Power, told ABC's This Week the unrest in eastern Ukraine "bears the tell-tale signs of Moscow's involvement."
In a statement, NATO chief Anders Fogh Rasmussen said he was "extremely concerned" about the increased tensions in the region. He described it a "concerted campaign of violence by pro-Russian separatists" seeking to destabilize Ukraine.
Fogh Rasmussen called on Russia to "de-escalate the crisis" and pull back thousands of troops it massed on its border with Ukraine.
On Saturday, U.S. Secretary of State John Kerry, in a telephone call with Russian Foreign Minister Sergei Lavrov, warned there would be additional consequences beyond sanctions already imposed against Russian officials if Moscow did not move to ease tensions in eastern Ukraine.
Lavrov said the crisis was caused by the Kyiv government ignoring the "legitimate needs and interests" of eastern Ukraine's Russian-speaking population.
A White House National Security Council spokeswoman said Saturday the United States is concerned that Russian-speaking separatists - with apparent support from Moscow - are "inciting violence and sabotage" against the Ukrainian state.
Moscow has repeatedly denied any role in Ukraine's unrest, which erupted in full two months ago when then-president Viktor Yanukovych fled the country amid protests in Kyiv.
Top diplomats from Russia, the United States, Ukraine and the European Union are set to hold emergency talks on the crisis April 17 in Geneva. White House officials say U.S. Vice President Joe Biden will travel to Kyiv April 22.