Ukrainian President Volodymyr Zelensky has said diplomacy will be more effective with "justice and strength" as trilateral talks in Geneva were due to start later.
"Strength of pressure on the Russian Federation - sanctions pressure and steady, rapid support for the Ukrainian army and our air defence," he wrote on social media.
Russian officials have arrived in the Swiss city for the talks with US and Ukrainian teams aimed at ending the four-year long conflict in Ukraine, a source within the Russian delegation told journalists.
The plane carrying the Russians, led by nationalist historian and former culture minister Vladimir Medinsky, landed in Geneva at around 6am, according to the source.
US President Donald Trump is pushing to end the conflict, but two previous rounds of US-mediated talks in Abu Dhabi did not yield any signs of a breakthrough.
Russia has stuck to its demands for sweeping territorial and political concessions from Ukraine - rejected by Ukraine as tantamount to capitulation.
Russia is pushing for Ukraine to pull out of the eastern Donetsk region - around one-fifth of which Ukraine's forces still control.
Ukraine has rejected a unilateral pull-back and wants robust western security guarantees to deter Russia from re-launching its offensive following any ceasefire.
Hundreds of thousands of soldiers and tens of thousands of civilians have been killed in the four-year conflict, Europe's deadliest since World War II.
Russia occupies around one-fifth of Ukrainian land - including the Crimean peninsula it seized in 2014 and areas that Moscow-backed separatists had taken prior to the 2022 invasion.
The talks in Geneva come as recent attacks by Russia have triggered Ukraine's worst energy crisis of the nearly four-year-old war, leaving hundreds of thousands of homes without heat and electricity at a time when temperatures have dropped as low as -20C.
Ukraine has also targeted Russian energy infrastructure with drone strikes, targeting the oil and gas industries helping to fund the invasion Moscow launched in February 2022.
