A third round of Ukrainian-backed peace talks opens in Malta on Saturday with representatives from more than 50 countries.
But Moscow, denouncing it as "a blatantly anti-Russian event" is staying away.
Ukrainian President Volodymyr Zelensky hopes the two-day meeting, held behind closed doors, will drum up support for his 10-point plan to end the war sparked by Russia's February 2022 invasion.
It follows similar summits in Jeddah and Copenhagen this summer.
National security and policy advisors from more than 50 countries plus international institutions are expected -- more than the 40-odd nations at the Saudi summit in August.
Kyiv sees the growing list of participants as a sign of global support for the process.
"This meeting is a powerful signal that unity is preserved around Ukraine," Andriy Yermak, the head of Ukraine's presidential office, said this week.
Russian foreign ministry spokeswoman Maria Zakharova however dismissed the Malta talks as a "blatantly anti-Russian event". They had "nothing to do with the search for a peaceful resolution", she said.
"Obviously such gatherings have absolutely no perspective, they are simply counterproductive," she told reporters on Thursday.
Global guest list
Zelensky's peace plan calls for Russia to withdraw all its troops from Ukraine's internationally recognised borders, including from the territory of Crimea, which it annexed in 2014.
Russia -- which claimed to annex the four Ukrainian regions of Lugansk, Donetsk, Kherson and Zaporizhzhia in September 2022 -- has rejected any settlement that would involve giving up land.
Organisers are hoping for a joint statement from the Malta summit, after both previous meetings ended without a final declaration.
Participants include the United States, the EU and Britain, staunch supporters of Kyiv, as well as Turkey, which has offered itself as a mediator between Ukraine and Russia.
Also attending are South Africa, Brazil and India, members of the influential BRICS bloc, which also includes Russia.
South Africa and India have not condemned the invasion, while Brazil has refused to join Western nations in sending arms to Ukraine or imposing sanctions on Moscow.
China, which insists it is neutral and refuses to criticise the invasion, was present in Jeddah and diplomats said there is hope it will take part in Malta.
The discussions would focus on five key areas -- food security, energy security, nuclear security, humanitarian issues and restoring the territorial integrity of Ukraine, Yermak said.
Both Russia and Ukraine are preparing for a gruelling winter ahead, with Ukraine warning of renewed strikes on its energy infrastructure and Russia pushing back against Kyiv's counteroffensive.