Ukraine's courts should rule on the results from the presidential runoff between Prime Minister Viktor Yanokovych and opposition leader Viktor Yushchenko.
Polish hero and Noble Peace Prize winner Lech Walesa flew into Ukraine on Thursday to meet the country's pro-Moscow president elect and try to mediate a growing political crisis that saw teachers strike and street rallies stretch into a fourth day.
Walesa said he believed "it is possible to arrive at a compromise" over the disputed election that has sparked a sharp confrontation between Russia and the West and seen Ukraine itself split into two highly-polarized regions.
Lech Walesa met Western opposition leader Viktor Yushchenko and was due to enter separate talks with president elect Viktor Yanukovich just as Russia and the European Union hunkered down for a tense summit in The Hague aimed at resolving their differences over Ukraine.