Ukraine crisis explained in 90 seconds
9 December 2013 Last updated at 13:38 GMT
Efforts are under way to defuse tensions in the Ukrainian capital Kiev, where riot police have been deployed on Independence Square, still occupied by thousands of anti-government demonstrators.
President Viktor Yanukovych says he is willing to take part in round table negotiations with the opposition; protesters are demanding the resignation of the government and fresh elections.
BBC Online's Europe analyst Laurence Peter explains the context of the crisis.
Video produced by Michael Hirst