Russia's President Vladimir Putin has said he will respect the outcome of Ukraine's presidential election.
Speaking in St Petersburg, he said Russia was prepared to work with whoever was elected Ukraine's president in Sunday's vote.
It is the first time Mr Putin has explicitly indicated that he will accept Ukraine's election result.
Violence in the east, particularly Donetsk and Luhansk, has seriously disrupted preparations for the polls.
Presidential candidate Yulia Tymoshenko, who is lagging behind frontrunner Petro Poroshenko in opinion polls, has called for a referendum to be held next month on Ukraine joining Nato, describing membership as a "strategic solution on how to bring peace back to Ukraine".
Nato chief Anders Fogh Rasmussen said in February, before the insurgency in eastern Ukraine erupted, that membership was still a possibility provided that Ukraine fulfilled the "necessary criteria". But with the absence of territorial disputes a key condition, Ukraine's friction with Russia over its annexation of Crimea are likely to overshadow any bid.
Some pro-Russian separatists in eastern Ukraine have warned people against voting, while election officials and voter lists have been seized at gunpoint.
At least 14 government soldiers were killed in clashes with pro-Russia separatists in the Volnovakha area south of the city of Donetsk on Thursday.
Ukrainian officials have also given details of an attack on a military base on Thursday involving hundreds of militants near the village of Rubizhne. According to the defence ministry, up to 20 separatists were killed.
One Ukrainian soldier was killed overnight in another attack on a military convoy in the same village, the ministry added.
Further deadly clashes were reported on Friday between pro-Russia separatists and self-defence fighters in the Donetsk region.
The presidential elections were called after the last elected president, Viktor Yanukovych, was deposed in February amid mass protests against his pro-Russian policies.
Analysis from BBC's Bridget Kendall in Moscow
This looks like an important signal from President Putin - an indication that even if he has not got everything he wanted, he now wants to end this crisis. Maybe it is to sidestep deeper sanctions and repair relations with the West, maybe because he is worried in case the violence in Eastern Ukraine spirals out of control, or even spills over the border into Russia itself.
It is no surprise that he has held out this olive branch at the St Petersburg Economic Forum, in front of some of Russia's biggest international partners and investors - an audience eager to be told that the Ukraine crisis will not affect their business prospects in Russia in the long term.
But Mr Putin's intentions have still to be matched by deeds. More violence in Ukraine could still knock any plans for peace off course. And after everything that has happened, it may not be as easy as he hopes to win back the confidence of Western governments.
It worked once, after Russia's brief war with Georgia in 2008. But it may not work a second time.
"We understand that the people of Ukraine want their country to emerge from this crisis. We will treat their choice with respect," President Putin told an economic forum in St Petersburg.
"It would have been better to hold a referendum and adopt a new constitution. Under the current constitution (Viktor) Yanukovych is still in power," he added.
Until now he has left open the possibility that Russia might question the election result on Sunday, says the BBC's diplomatic correspondent Bridget Kendall.
But now he has left little doubt that he has decided to accept the outcome, even if somewhat reluctantly, she adds.
Mr Putin also voiced concern that Ukraine would join Nato and said that he hoped the leadership in Kiev would end military action in eastern Ukraine.
He said he believed Ukraine had descended into "full-scale civil war" but denied that Moscow was behind acts involving pro-Russia separatists.
Mr Putin was also critical of United States policy on Ukraine, saying Washington "had dropped Ukraine in a mess", accusing the US of encouraging the removal of pro-Moscow President Viktor Yanukovych.
Independence referendums were held in Donetsk and Luhansk earlier this month, even though Mr Putin had urged a delay to the votes days before.
The 11 May votes were not recognised by Kiev and its Western allies but separatists declared independence soon afterwards.
Moscow said it respected the results and called for the peaceful "practical implementation" of the "will of the people".
Russia annexed Crimea from Ukraine soon after a disputed referendum in March.