Tens of thousands of people have packed the streets of Ukraine's capital, Kiev, to protest the result of Sunday's presidential election.
Ukrainian security forces say they are ready to prevent any eruption of violence.
Some local officials are also refusing to recognize Prime Minister Viktor Yanukovych who election officials say beat pro-western candidate Viktor Yushchenko by three percentage points. (49.42 to 46.7 %)
Kiev's city council has called on parliament to reject the results, and local officials in Lviv and Ivano-Frankivsk also have discounted the official tally.
A spokesman for the Kremlin says Russian President Vladimir Putin congratulated Mr. Yanukovych on the election, while European and American observers have expressed concern about the vote.
U.S. Senator Richard Lugar, who monitored the election for the Bush administration, says authorities conducted what he calls a "concerted and forceful program" of election day fraud and abuse.
The U.S. State Department noted problems in the electoral process and said quick and decisive action is needed.