Western diplomats have scrambled to stave off an economic collapse in Ukraine, as Russia pledged not to intervene in the crisis-hit country after the dramatic ouster of pro-Moscow leader Viktor Yanukovych.
The bloc's foreign policy chief Catherine Ashton travelled to Kiev and met with temporary, pro-West leader Oleksandr Turchynov as well as members of parliament, which called on Tuesday on the International Criminal Court in The Hague to prosecute Yanukovych.
Her trip is just the public tip of furious closed-door talks taking place between US, European and Russian diplomats over a country that has appealed for $US35 billion ($A38.8 billion) in aid to avoid bankruptcy and which according to Turchynov is facing a secessionist threat.
"We offer support, not interference for the future," Ashton told reporters in Kiev amid fears Ukraine's pro-Russia east could agitate for partition after a pro-Western administration took charge of the country following months of protests.
She also stressed "the importance of the strong links between Ukraine and Russia and the importance of having them maintained".
Russia had initially reacted with fury to the weekend's rapid-fire political changes - brought about by deadly clashes in Kiev last week that left nearly 100 dead - accusing the new leadership of waging an "armed mutiny".
But on Tuesday Russian Foreign Minister Sergei Lavrov sought to soften the tone, saying Ukraine should not be forced to choose between Russia and the West.
The tumultuous events of the past week have capped more than three months of relentless protests against Yanukovych's rule sparked by his November decision to spurn an historic pact with the European Union in favour of closer ties with Russia.
