Germany has called for EU sanctions against the Ukrainian leadership, and Poland, Sweden and Lithuania have hinted they would support the initiative.

German Foreign Minister Frank-Walter Steinmeier, who earlier opposed such action, said on Tuesday that "those responsible in these hours for more bloodshed must know that the restraint Europe has shown regarding personal sanctions will surely be reconsidered," as EUObserver reports.

By sanctions, Germany means the freezing of assets held by top Ukrainian politicians, including President Viktor Yanukovych, former PM Mykola Azarov, and Yanukovych's son Oleksandr, who has numerous properties and business ventures in Europe.

Calls for European measures were indirectly echoed by the Polish Foreign Minister Radek Sikorski, who assured in an interview for a Polish radio that the violence in Ukraine will "definitely have consequences" for the authorities and that Europe "will act with a cool head" on the matter.

"The EU will not hesitate on measures against interests of persons associated with repression and violence", his Swedish counterpart Carl Bildt commented.

EU Neighborhood Commissioner Stefan Fuele has already expressed his shock at the events in Ukraine, but refrained from commenting further on.

Brussels has so far only condemned the escalation of violence in Ukraine, but has expressed its readiness "to respond quickly to any deterioration on the ground".

Ukraine's reaction to European comments was more than clear, as president Yanukovych declined to answer phone calls from German Chancellor Angela Merkel and EC President Jose Manuel Barroso.

US vice-president Joe Biden, however, did communicate to Yanukovych on the phone and reportedly said to him that "the United States condemns violence by any side, but the government bears special responsibility to de-escalate the situation".

Further reaction from European leaders is expected as the German Chancellor meets French President Francois Hollande in Paris on Wednesday.

European and US stance toward the Ukrainian crisis has been harshly criticized by Russia, as yesterday the Foreign Ministry referred to the unrest on its website as "a result of the intervention of Western politicians and European structures" in Ukrainian domestic affairs.

At least 25 people have been killed as a result of the renewed unrest in Ukraine over the last 24 hours. More than 240, among them 79 police officers and five journalists, have been taken to hospital. The violence, which first started in Kiev, has spread to the western cities of Lviv, Ivano-Frankivsk and Ternopil.

The protests began in late November after President Viktor Yanukovych rejected a deal with the EU and turned to Russia for financial help.