Russia does not trust Viktor Yanukovich, but has stood by the Ukrainian president since demonstrators occupied Kiev's Maidan square three months ago.
However, as deadly clashes between demonstrators and police erupted in Kiev and other Ukrainian cities this week, the Kremlin appeared to be losing confidence in Mr Yanukovich’s ability to win the battle for power.
After a phone conversation with the Ukrainian president yesterday, Vladimir Putin appointed Vladimir Lukin, Russia's outgoing ombudsman, as his special envoy to Kiev with instructions to mediate with the government and the opposition.
Protesters first occupied the Maidan after Mr Yanukovich ditched a plan to sign a trading agreement with the European Union. Instead, Mr Yanukovich accepted a $15 billion bailout from Russia, and Ukraine’s opposition is convinced Mr Putin blackmailed Mr Yanukovich to dump the EU deal.
Strategic battle
The stakes are high for the Kremlin, with the fate of Ukraine now widely seen as part of a strategic battle between authoritarian Russia and the liberal west.
Three EU foreign ministers visited Kiev for talks with Mr Yanukovich to promote a political settlement of the crisis. Sergei Lavrov, Russia's foreign minister, slammed the talks as the "latest uninvited mission" by the EU to Ukraine.
Dmitry Medvedev, Russia's prime minister, called on the Ukrainian government to restore order and not to bow to pressure from outside. "We will do everything to fulfil the pledges which we gave them," he told a government meeting.
Mr Medvedev appeared impatient with Mr Yanukovich’s handling of the affair. It was important, he said, that the Ukrainian authorities were “legitimate and effective so that people don’t wipe their feet on them like a doormat”.
Mr Putin does not usually negotiate with opposition activists and the appointment of Mr Lukin, known as a moderate, surprised many.