Ukrainian President Viktor Yanukovych has insisted that he and his government have "fulfilled all the obligations" to solve the crisis in the country. But the political opposition continued to "whip up" the situation, he added.

According to BBC News, the defiant statement was issued on the presidential website (Ukrainian) after weeks of often-violent anti-government protests in Kiev and other cities led to a series of government concessions.

It followed an announcement that Yanukovych, 63, was on sick leave. The presidential website said he had a respiratory illness and a high fever.

The protests began in November after President Yanukovych reversed a decision to sign a trade deal with the European Union, instead favouring a $15bn bailout deal with Russia.

Anti-government protesters are still occupying government buildings and manning barricades in freezing temperatures in the centre of the capital Kiev.

The past week has seen President Yanukovych accept the resignation of the prime minister and his cabinet, and offer senior jobs to the opposition - offers that were rejected.

And the country's parliament has voted to annul a recently enacted law restricting protests, which appeared to be inflaming the situation, and pass an amnesty law for detained protesters under the condition that occupied buildings were vacated.

"We have fulfilled all the obligations which the authorities took on themselves," President Yanukovych said in the statement.

"However, the opposition continues to whip up the situation calling on people to stand in the cold for the sake of the political ambitions of a few leaders. I think this is wrong."