Ukrainian President Viktor Yanukovych (second from left) looks at the life-sized terracotta warriors in Xi'an, capital of Northwest China's Shaanxi Province on Wednesday. Photo: AFP/Ukrainian Presidential Press Service - Muykhylo Markiv

Ukraine's embattled Prime Minister Mykola Azarov warned protesters on Wednesday they would be punished if they broke the law after he marshaled his ministers for a cabinet meeting despite an attempted blockade by demonstrators.

As a result of the government's rejection of closer ties with the European Union, tension stayed high in Kiev as black-helmeted riot police sealed off the approach road to the main offices of President Viktor Yanukovych, confronting several hundred protesters from behind steel barriers.

Protesters had threatened to tighten their blockade of key buildings in Kiev on Wednesday. Yanukovych himself flew to China on Tuesday.

The crisis has exposed once more the East-West tug-of-war playing out in Ukraine, which has oscillated between the EU and Moscow since the 2004-05 Orange Revolution overthrew the post-Soviet political order.

Azarov's government survived an attempt to topple it in parliament on Tuesday in a rough encounter with opposition parties.

At the cabinet meeting on Wednesday, Azarov said the government had demonstrated tolerance and a readiness for dialogue during the protests and he urged all political forces to avoid a further escalation of tension.

"Everybody must realize that the country's constitution and laws are in force, nobody is allowed to violate them ... All those who are guilty of illegal acts will answer for them," he said.

International markets kept up the pressure, driving the cost of insuring Ukrainian debt against default to a level not seen since January 2010. Ukraine faces gas bills and debt repayments next year of more than $17 billion.

Ukraine's Deputy Prime Minister Yuri Boiko departed for Moscow on Wednesday for talks on bilateral issues including natural gas, the Interfax news agency reported.

While hosting the Ukrainian delegation, Russian Prime Minister Dmitry Medvedev said, "Of course this is an internal matter, but it is very important that there be stability and order in the country."

Regarding Yanukovych's visit, China's foreign ministry spokesperson Hong Lei didn't directly address the question of whether Beijing would provide any aid to Ukraine. He only said that leaders from both sides will "exchange comprehensive views on subjects of mutual interests."

The US also weighed into the crisis on Tuesday.

"We urge the Ukrainian government to listen to the voices of its people who want to live in freedom and in opportunity and prosperity," US Secretary of State John Kerry said. "We urge all sides to conduct themselves peacefully. Violence has no place in a modern European state."