KIEV -- President Leonid Kuchma won crucial political support yesterday from President Vladimir Putin of Russia, who sided with him in rejecting an opposition demand to rerun the presidential runoff held 11 days ago.
The call for a new vote, after widespread allegations of fraud in the Nov. 21 balloting, has been at the core of mass demonstrations in Kiev in favor of opposition leader Viktor Yushchenko.
The United States and the European Union favor another election.
Kuchma flew to Moscow and told Putin at an airport meeting, ''I do not know a single country whose laws would allow such a rerun."
Putin concurred, saying: ''A repeat of the runoff vote may fail to work. A rerun can be held twice, three times, 25 times until one of the parties gets the desired result."
Putin had backed Kuchma's candidate, Prime Minister Viktor Yanukovych, and visited Ukraine twice during the campaign to support him. Yanukovych ran on a platform of close relations with Moscow, a stand that fits with Putin's view that Ukraine is part of the ''near abroad" of former Soviet republics within Russia's sphere of influence.
Yanukovych was officially declared the winner of the runoff by about 3 percentage points, but international monitors agreed with Yushchenko that the process was plagued by fraud and Ukraine's parliament subsequently declared the vote invalid.
In Washington, President Bush indirectly criticized Russia's role in the crisis. ''I think any election, if there is one, ought to be free from any foreign influence. These elections ought to be open and fair," Bush said in response to a reporter's question about the prospect of Russian influence on a new vote in Ukraine.
The US government has been eager to avoid conflict with Putin, whom Bush regards as an ally in the war on terrorism. But the political crisis in Ukraine has divided the country between the east, where many ethnic Russians and pro-Moscow Ukrainians reside, and the west, the base of support for Yushchenko, who regards ties with NATO and the EU as the source of the country's future prosperity.
Kuchma has emerged as a key player in the crisis and the main target of opposition criticism. The question of his intentions has eclipsed the issue of Yanukovych's candidacy, Western diplomats said.
Kuchma, a former Soviet factory director who is closely tied to the Russian government, decided not to seek reelection. He has served as president since 1994, all but three years of Ukraine's independence, and his opponents have accused him of leading a corrupt system dominated by major businessmen.
''Kuchma is the pivotal figure," said a senior Western diplomat speaking on condition of anonymity. ''Where he puts his effort may be decisive. To stall is part of it, but he still holds out hope that someone from his side could be president."
Kuchma has endorsed the idea of new elections but wants them to start from scratch, which would open the field to new candidates and give him time to organize and fund a campaign.
During an evening rally at Independence Square in Kiev, Yushchenko, a former prime minister who once headed the central bank, told tens of thousands of supporters that he would not engage in talks based on Kuchma's proposal. ''Only a rerun of the election can save the state," he said. ''They are testing our patience and nerve."
The day before, Yushchenko had appealed to backers to abandon sieges at government buildings. But yesterday, offices that were blocked by hundreds of people on Wednesday remained obstructed. Demonstrators wore ribbons and scarves of orange, Yushchenko's campaign color.
Many Yushchenko supporters consider Kuchma the main villain of the election, and his trip to Moscow yesterday caused deep resentment. ''Kuchma and Putin can't be allowed to run the country," said Andrei Yurchenko, a computer technician carrying a Ukrainian flag among protesters outside the Supreme Court.
''It's OK to negotiate, but it must be made clear that the terms are of surrender of the criminal authorities," said Sergei Shandrenko, a colleague of Yurchenko's.
Unlike at other offices, demonstrators at the Supreme Court left a corridor for functionaries to enter. The court heard final arguments yesterday on Yushchenko's suit to invalidate the Nov. 21 vote. A decision could be announced as early as today.
In remarks yesterday to government ministers, Kuchma held out a carrot to Yushchenko: If the opposition leader agrees to elections from scratch, Kuchma would endorse a ''shorter time frame" for the vote. Under law, elections cannot take place until three months after they are announced.