Ukraine's opposition has pulled out of talks with Prime Minister Viktor Yanukovych on ending the country's political crisis.
The announcement came amid continued opposition protests over charges of widespread fraud after Mr. Yanukovych was declared the winner of the November 21st vote.
Opposition candidate Viktor Yushchenko says the vote was rigged and is challenging the results in Ukraine's Supreme Court, which could order a new election.
Talks collapsed Tuesday when the pro-western Mr. Yushchenko rejected an offer to become the new prime minister in a Yanukovych presidency.
The disputed election is threatening to split Ukraine apart. Lawmakers in pro-Russian eastern Ukraine are threatening to declare autonomy if Mr. Yanukovych does not become president.
European leaders are converging on Ukraine to mediate. They include European Union foreign policy chief Javier Solana and Polish President Aleksander Kwasniewski.
President Bush has said the will of the Ukrainian people must prevail.