Britain said today it would support a new government in Ukraine once one is formed and called for an IMF package to help the country recover from the three-month crisis.
Foreign Secretary William Hague said he was in close touch with European Union partners over what he called the "extraordinary developments" in Ukraine.
"Events in the last 24 hours show the will of Ukrainians to move towards a different future, and ensure that the voices of those who have protested courageously over several months are heard," Hague said in a statement.
"We will work closely with our EU partners in support of a new government in Ukraine, as and when that is formed.
"In the meantime it is important that Ukraine's political leaders respond to events calmly and with determination to harness the united efforts of all Ukrainians to work together for a successful future."
He said the release of jailed pro-Western opposition icon Yulia Tymoshenko was welcome.
In a tweet, Hague said he had agreed with his German counterpart Frank-Walter Steinmeier to push for a "vital" International Monetary Fund financial package for debt-laden Ukraine.
A Foreign Office spokeswoman said: "One of the things they talked about was the economic situation and putting together a financial package which will help to stabilise the situation in Ukraine, to enable the Ukraine to receive long-term support from the IMF."
Ukrainian President Viktor Yanukovych refused to step down Saturday and denounced a "coup" by protesters as the emboldened opposition took control of parliament and parts of Kiev in another dramatic turn in the crisis.
Yanukovych's regime appeared close to collapse as protesters took control of his offices and lawmakers voted to free former premier Tymoshenko immediately.
