An election is scheduled May 25 to elect a new Ukrainian president for a five-year term. Originally scheduled for March 29, 2015, the date was moved following countrywide protests, after the former, pro-Russian president’s decision to reject closer EU ties.

The interim prime minister, Arseniy Yatsenyuk, belongs to the same party, Fatherland, as the current acting president, Oleksandr Turchynov — in power since Viktor Yanukovych was ousted on Feb. 22.

Major civil unrest in the pro-Russian areas of the country could make voting difficult, especially with pro-Moscow separatists having de facto control of several southeastern towns. Moscow's annexation of Crimea — where the election is also happening, in principle — has deepened the worst East-West rift since the Cold War.

Due to security concerns, Ukraine’s Interior Ministry has divided the country into white, pink and red zones — corresponding, respectively, to safe, risky and violent areas of the country. Special rapid-response units will be working in the most conflict-prone regions, and police will be deployed throughout the vote-counting. With some voting commission buildings seized and many government offices occupied by rebels, the process will be challenging.

The Warsaw-based Office for Democratic Institutions and Human Rights (ODIHR) has deployed 900 observers to monitor the election. A tenth of the officials are from the U.S., and Washington has provided $11.4 million to make the poll “free and fair.”

With Petro Poroshenko leading by a large margin in polls, a total of 21 candidates are officially running. Three dropped out but are still listed on ballots because they withdrew too late. Seven of the candidates have been chosen by political parties, and candidates needed to nominate themselves to the Central Election Commission with a final registration deadline of April 4. If necessary, a run-off between the two leading contenders will be held June 15.