Pro-Western parties were expected to sweep parliamentary elections in Ukraine, exit polls showed, tilting the embattled former Soviet republic further toward Europe and away from Russia.
Leaders in President Petro Poroshenko 's party, which exit polls showed won the most support on Sunday, said it would form a coalition with other pro-European parties, which together appeared set to hold an overwhelming majority in the chamber for the first time.
But the new government will face immense challenges, not least the Kremlin's unwillingness to countenance Ukraine's efforts to forge closer economic and political ties with Europe. Russia annexed Crimea and has supported a separatist insurgency in Ukraine's east after a pro-European protest movement ousted the country's Moscow-backed president in February.
Ukraine's economy could slide as much as 10% this year, and officials say they will likely have to seek an expansion of a $17 billion lending program from the International Monetary Fund. Russia has cut off gas supplies amid a payment dispute and has given no sign it is pressing separatists to adhere to a peace deal agreed upon last month.
Mr. Poroshenko's party appeared to win 23.1% of the vote, according to exit polls by a consortium of Ukrainian pollsters. The showing was weaker than forecast, as the party of Prime Minister Arseniy Yatsenyuk, a pro-Western economist who has taken a strongly anti-Russian stance in recent weeks, notched a stronger-than-anticipated 21.2% of votes, based on the exit polls. Official results weren't expected until Monday.
"More than three-quarters of voters who took part in the election powerfully and irreversibly supported Ukraine's course toward Europe," Mr. Poroshenko said in an address.
Mr. Poroshenko said his team had already prepared a coalition agreement and wanted a speedy formation of a government. In a Twitter post, he said he wanted to join with Mr. Yatsenyuk's People's Front in a coalition. Mr. Yatsenyuk said he also wanted to form a coalition "in the shortest time." Another People's Front leader said Mr. Yatsenyuk should retain his post as prime minister.
The elections called by Mr. Poroshenko and aimed at supporting his attempts to end a conflict with Russia-backed separatists in the country's eastare the first since the ouster of Mr. Poroshenko's pro-Moscow predecessor, Viktor Yanukovych, who fled to Russia during mass street protests in February. The vote is likely to clear out many of Mr. Yanukovych's allies from parliament and usher in the most pro-Western chamber in Ukraine's 23 years of independence.
The elections come amid clashes in Ukraine's east, which are continuing despite a cease-fire. Pro-Moscow separatists didn't allow voting in the territories they hold. There was also no voting in Crimea, which Russia annexed in March, meaning only 423 out of 450 seats in the chamber will be filled, according to election officials.
Turnout fell to 52.5% of eligible voters from 58% in 2012, official data showed.
Pro-Western parties will dominate the new parliament, according to the exit polls. The only pro-Russia party expected to make it into the new parliament will be the Opposition Bloc, with 7.6% of the vote, the polls indicated. The Communist Party appeared set to fall short for the first time since Ukraine's independence.
The exit polls also showed a surprisingly strong result for Self-Help, a new pro-Western party headed by the mayor of the western city of Lviv, with 13.4%.
The Radical Party, led by populist Oleh Lyashko, performed worse than forecast, with just 6.4%, according to the exit polls, which also indicated that pro-Western parties Freedom and Fatherland would cross the 5% barrier to take seats in parliament.
Half the seats in parliament are decided by party lists; the rest are individual lawmakers elected in districts across the country.
More than 100 of those elected in districts will join the coalition, said Volodymyr Fesenko, a political analyst in Kiev.
Many voters said they were voting to rejuvenate a parliament widely viewed as corrupt, incompetent and incapable of passing large-scale overhauls of the country's moribund economy and administrative system.
Serhiy Krupka, a 42-year-old entrepreneur who cast his ballot in downtown Kiev, said he voted for "new faces," without specifying which party. But he said he was concerned there wouldn't be enough of them in the parliament to change the situation.
The overthrow of Mr. Yanukovych was hailed as a potential turning point for Ukraine to break free from Moscow's grasp. But the Russian intervention has shifted focus from much-needed economic and administrative overhauls to fighting for the country's survival.
Mr. Poroshenko, who agreed to a peace deal with Russia and the rebels last month, donned fatigues on a visit to Kramatorsk in Ukraine's east, just a few miles from the front lines.
Election observers from the Committee of Voters of Ukraine and Opora said the atmosphere was mostly calm. "No mass violations of the election legislation and or procedures have so far been registered," the groups said in a statement.
The groups reported isolated incidents, such as the interference of armed men at one polling station in an eastern town and the stoning of a car carrying three candidates allied with Mr. Poroshenko.
In the east, allies of Mr. Yanukovych picked up most votes, but turnout there was significantly down from previous elections, in which pro-Russia parties dominated the region. At a polling station in the center of the mining town of Krasnoarmiisk in the east, election officials sat idle as voters arrived in ones and twos.
"People in Kiev have never been down mines and don't know what it's like," said Irina Vasileva, head of the election commission at the polling station. "We feel like Ukraine doesn't want us and DNR doesn't want us," she said, referring to the separatist Donetsk People's Republic a few miles away.
Others said they hoped the elections would help break the grip of former allies of Mr. Yanukovych on the region's economy and politics. Vladimir Bigvava, a 43-year-old businessman, said he voted for Self-Help. "They are new faces," he said. "Maybe they'll be better, maybe they won't. God knows."