Ukrainian Prime Minister Mykola Azarov has warned the opposition to stop its escalation of political tensions as protesters continue to demand his government's resignation.
Azarov, speaking at a cabinet meeting on December 4, also warned protesters who are blockading government buildings that anyone found guilty of violating Ukrainian law or the constitution will face punishment.
With protesters picketing government headquarters outside, Azarov claimed that "the reasons for street protests have been exhausted."
"Certain political forces without any constructive agenda are directing street protests, inciting violence, unlawful occupation of administrative and communal buildings, blockades of state institutions. This is a criminal offense," Azarov said.
"I want to ask the so-called leaders of street protests: 'Who will assume responsibility for these crimes? Who is ready to bear criminal responsibility?' I call on these so-called leaders not to hide behind people's backs but to publicly and clearly state who personally will be responsible for this," he added.
Meanwhile, opposition lawmakers disrupted the December 4 session of parliament and vowed to continue to block the legislature until their demands are met.
The opposition is demanding that the government step down over its decision not to sign an agreement on closer ties with the European Union and over a violent police crackdown on the resulting demonstrations.
WATCH: Opposition protesters march in Kyiv.
President Viktor Yanukovych suspended preparations on signing association and free-trade accords with the EU just days before it was supposed to be signed at a summit at the end of last month.
The decision sparked the biggest protests in Ukraine since the 2004 Orange Revolution. On December 1, at least 350,000 rallied on Kyiv's Independence Square after a violent police crackdown on demonstrators a day earlier.
Yanukovych defended his decision to back out of the deal, saying Ukraine could not afford to sacrifice close trade ties with Russia, which had opposed the Ukraine-EU pact.
The opposition on December 3 failed to push through a parliamentary vote of no-confidence in the government but vowed to continue protests.
Several thousand protesters remained on Independence Square on December 4.
Nine activists have been arrested over weekend clashes between protesters and police in Kyiv.
WATCH: Government supporters stage counterdemonstration in Kyiv.
Meanwhile, Ukrainian Deputy Prime Minister Yuriy Boyko was in Moscow for talks on bilateral issues, including natural gas.
Ukraine has been seeking lower prices on Russian gas supplies, possibly a key pressure point in any dealings between Kyiv and Moscow.
Russian Prime Minister Dmitry Medvedev, after his meeting with Boyko, said Moscow wants "stability and order" in Ukraine.
For his part, Russian Foreign Minister Sergei Lavrov, speaking after a meeting with NATO foreign ministers in Brussels on December 4, urged outsiders not to interfere in the political crisis in Ukraine. He said he did not understand why NATO found it necessary to condemn the Ukrainian authorities for using excessive force against protesters.
"[Russia] considers it a Ukrainian internal affair. I do not understand the scope of rather aggressive opposition actions," Lavrov said. "I count on Ukrainian politicians to come up with a way to return the situation into the constitutional framework -- that's what we stand for -- and call on everyone to refrain from meddling in this situation."
Also speaking at the NATO meeting, Ukraine's ambassador to the alliance, Igor Dolgov, told the alliance's ministers that he saw no crisis at all.
"What I see and the news I receive from Kyiv is [concerning a] mass demonstration of people in support for the European integration of Ukraine. This is exactly the main foreign-policy course that my president and acting government continue to implement, so I see no crisis," Dolgov said.
"I see the desire of the population, especially of the Ukrainian youth, to accelerate the process or the rapprochement with the European Union and signing of the Association Agreement as soon as possible."
Despite the events at home, Yanukovych is on a visit to China, where he is seeking economic deals.
With reporting by AFP and Reuters