Russian Foreign Minister Sergei Lavrov has said if Ukraine were to go ahead with plans to crackdown on pro-Russian separatists in the eastern part of the country, this would undermine peace talks between the two countries that are scheduled for Thursday in Geneva.

"One cannot issue invitations to talks while at the same time issuing criminal orders for the use of armed force against the people there," Lavrov said during a visit to Beijing. "You can't send in tanks and at the same time hold talks, and the use of force would sabotage the opportunity offered by the four-party negotiations in Geneva."

The separatists in almost ten cities in the eastern part of the country have occupied government buildings and set up barricades to prevent security forces from retaking them. The region consists mostly of Russian speakers, and many have expressed their desire to join Crimea in breaking away from Ukraine and becoming a part of Russia.

On Tuesday, Ukraine's acting president, Oleksandr Turchynov, said there would be an "anti-terrorist operation" to stop the separatists. He said Russia had plans for "the whole south and east of Ukraine to be engulfed by fire," and that the aim of the operation would be to "defend the citizens of Ukraine, to stop terror, stop crime and stop attempts to tear our country into pieces."

An ultimatum issued on Monday telling the armed separatists to lay down their arms did not seem to have much of an effect. Ukrainian troops have not yet made a move to storm the occupied buildings, and the Associated Press reports that the city of Horlivka, near the Russian border, has had its police station occupied by separatists.

Calling for calm until meeting

The foreign ministers of the United States, Ukraine, and Russia, along with the EU's foreign policy chief Catherine Ashton, are scheduled for talks on Thursday to seek a diplomatic path toward deescalating the situation.

On Tuesday, EU defense ministers met in Luxembourg, and the issue of the conflict was addressed.

German defense minister Ursula von der Leyen called on Russia to show "clear and definite signs of deescalation".

"We are here to work on a political solution to this difficult crisis in the Ukraine," she said, "just like we expect Russia to do everything to distance itself from a further destabilization of Ukraine."

In an interview with the German newspaper Die Welt, Foreign Minister Frank-Walter Steinmeier made similar comments.

"It would be good if Russia distanced itself from the violent and unlawful actions of pro-Russian demonstrators," he told the paper.

mz/rg (dpa, AP, AFP)