Russian Foreign Minister Sergei Lavrov on Monday accused the government in Kiev of breaching an international accord reached last week aimed at defusing the crisis in Ukraine.
"The Geneva accord is not only not being fulfilled, but steps are being taken, primarily by those who seized power in Kiev, that are grossly breaching the agreements reached in Geneva," Lavrov said at a televised news conference in Moscow.
He spoke after a warning from Washington that time was running out for implementing the agreement hammered out last Thursday in Geneva between Russia, Ukraine, the United States and the European Union.
US President Barack Obama had warned Russia that it would face additional sanctions if progress was not made within days.
But Lavrov dismissed the risk of Russia falling into greater international isolation.
"Attempts to isolate Russia have absolutely no future because isolating Russia from the rest of the world is impossible," he said.
He said Kiev authorities had not granted an amnesty to arrested protesters, as required by the Geneva deal.
"Instead of freeing those already arrested, particularly the 'people's governor of Donetsk', Pavel Gubarev, the authorities in Kiev are continuing to arrest political figures from the southeast," Lavrov said.
He also said calls by Ukrainian MPs to preserve a protest camp on Kiev's central Independence Square, known as the Maidan, were "absolutely unacceptable", saying "even under Ukrainian law, such things cannot be done."
He acknowledged the complaint from the Kiev authorities that pro-Russian forces were not fulfilling their part of the agreement, but accused the government of taking no action to end the conflict.
"They are complaining about the southeastern regions, saying that they are not freeing buildings and removing roadblocks, but the authorities are doing nothing, they haven't lifted a finger to get rid of the reasons that lie at the basis of the current deep crisis inside Ukraine," he said.