The November 21 presidential election brought Russia-backed candidate Viktor Yanukovich to power, despite exit polls showing pro-Western opposition leader Viktor Yushchenko leading by at least 11 percent.
With over 99 per cent of the vote counted, official results gave Yanukovych 49.39 per cent and Yushchenko 46.71 percent.
As the US and the European Union denounced the election as rigged, Russian President Vladimir Putin warned outsiders against interfering in the affairs of the Ukraine, saying it did not need to be 'lectured.'.
Three days of street protests in Kiev culminated with an estimated 200,000 protestors laying siege to the snow-capped
Addressing an emergency session of the opposition in parliament, he said Ukraine was on the threshold of a civil conflict, and "we have two choices: either the answer will be given by the parliament, or the streets will give an answer."
Latest reports said some of the protestors started clearing out of the area Wednesday after outgoing president Leonid Kuchma called for negotiations with the opposition.
According to one report, the US summoned the Russian ambassador to explain why they had endorsed a victory for Mr Yanukovich before the official results were announced. A Russian official reportedly hit back by condemned this "unprecedented interference" in domestic affairs.