KIEV, Feb. 11 – U.S. President Barack Obama, along with other world leaders, on Thursday called Ukrainian opposition leader Viktor Yanukovych to congratulate him with the victory at Sunday’s presidential election, his Regions Party announced.

This comes as a setback for Prime Minister Yulia Tymoshenko, the defeated candidate, who has been mounting a legal challenge to contest – and perhaps to reverse - the vote.

The developments show the world leaders accepted the ruling by international election monitors that the vote was free and fair, disregarding Tymoshenko’s claims that the election was “one of the dirtiest” in Ukraine’s history.

Other leaders calling Yanukovych included European Commission President Jose Manuel Barroso, French President Nicolas Sarkosy, Polish President Lech Kaczynski and Georgian President Mikhail Saakashvili, according to the Regions Party.

Russian President Dmitry Medvedev called Yanukovych earlier this week to congratulate him on his “successful performance” at the election.

The phone calls from world leaders add legitimacy to Yanukovych as president-elect, while the Central Election Commission has yet to officially declare him the winner.

With votes from 100% of the polling stations counted, Yanukovych won 48.95% of the vote, compared to Tymoshenko's 45.47%, the Central Election Commission said.

Another 4.36% of ballots were cast "against all," a legal option in Ukraine. Some 1.19% of ballots were spoiled.

Though official and comprehensive, these results must still be double-checked and formally certified by the election commission, a process which may take several more days.

Obama “highly appreciated the level of democracy in Ukraine that had been confirmed by the presidential election,” the Regions Party said.

Yanukovych assured Obama that “partner relations between Ukraine and the U.S. will dynamically develop based on trust and mutual respect,” the Regions Party said.

Saakashvili told Yanukovych: “I believe in your success at the highest post. This proves once more that Ukraine is moving towards strengthening democratic values and liberties.”

Kaczynski invited Yanukovych to visit Poland upon his earliest convenience.

Meanwhile, the outpour of support for Yanukovych angered Tymoshenko, who had been seeking to re-count about one million ballots at more than 900 polling stations throughout Ukraine.

“This is unethical,” Boris Tarasiuk, the head of Rukh party and an ally of Tymoshenko, said. “The official [election] results are not there yet.”

Tarasiuk drew parallel with the infamous 2004 presidential election when Vladimir Putin, then the Russian president, had called Yanukovych twice to congratulate him with victory that had never materialized.

World leaders refused to accept Yanukovych’s victory in 2004 to massive fraud, and in the court-ordered re-run of the runoff Yanukovych was defeated by Viktor Yushchenko.

“This reminds me the situation of 2004 when Putin had twice called Yanukovych to congratulate [with the presidency], but this had never happened,” Tarasiuk said. (tl/ez)