Ukraine's President Viktor Yanukovich is set to return to work on Monday after a period of sick leave, a statement on the presidential website said. Thousands of anti-government protesters have gathered in central Kiev to demand his resignation.
Russian Foreign Minister Sergei Lavrov urged European governments not to interfere in Ukraine's political crisis and expressed concern that events in Kiev could be spinning out of control.
Moscow, which sees its fellow former Soviet republic as part of its traditional sphere of influence, has watched nervously as protests against President Viktor Yanukovich's decision to shun a trade pact with the European Union have turned violent.
Yanukovich, who received a multi-billion dollar bail-out package from Moscow after he spurned the EU deal, has angered protesters by signing sweeping laws to curb public protest.
Ukraine has experienced difficult days before but few have been so complex or so pivotal.
The Ukrainian government says it is is ready to use all tools available to restore order if violence and unrest continues.
These are difficult days for Ukraine, a country edging toward its second revolution in a decade.