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.
Germany has summoned the Ukrainian ambassador in Berlin to demand an end to the government's use of force against pro-European integration demonstrators, a foreign ministry spokesman said.
"The aim of this summons is to make clear to Ukraine's official representative in Germany what the position of the German government is," spokesman Martin Schaefer said.
"We expect Ukraine's ambassador to pass on this message without delay to his government, the president and the prime minister," he added.
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.