The EU says it is putting on hold work on a key trade agreement with Ukraine, saying the government's arguments have "no grounds in reality". Protesters have taken to the streets in support of the agreement, which was rejected by the government.
Supporters of Ukrainian President Viktor Yanukovych have rallied in central Kiev, waving flags and displaying placards of the their leader's political party, the Party of Regions.
There is an urgent need for de-escalation in Ukraine as President Yanukovich tries to calm a country bitterly divided over years of history.
Ukraine's political and economic landscape is stuck between old Soviet masters in Russia and the democratising ideals offered by the EU.