"It doesn't look like there were any mass irregularities," Pavel Koval said.
He said the mission was still collecting reports from local monitors and would deliver its report later today.
He stressed the importance of thoroughly monitoring the vote count, and noted a slight difference in the results of both candidates.
Kowal declined to forecast whether Prime Minister Yulia Tymoshenko, who lost the presidential run-off election to opposition leader Viktor Yanukovych according to preliminary results, would recognize her defeat.
With 95.76% of ballots from district election commissions counted, Yanukovych garnered 48.28% of the vote and Tymoshenko received 46.11%, according to the press center of the Central Election Commission.
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