Ukrainian President Volodymyr Zelensky has called for "real, lasting peace" this year as European leaders gathered for a summit in Kyiv on the third anniversary of Russia's invasion.
Russia has said it would halt the invasion only if a deal could be reached that "suits" its interests, and accused Europe of wanting to prolong the fighting.
Russian President Vladimir Putin's decision to launch the invasion in February 2022 set off the biggest conflict in Europe since World War II.
Tens of thousands of soldiers on both sides and Ukrainian civilians have been killed. Cities across the country's south and east have been flattened and millions forced to flee their homes.
"This year should be the year of the beginning of a real, lasting peace," Mr Zelensky told Ukraine's backers in Kyiv.
"We have to win peace through strength and wisdom and unity," he said, vowing at a press conference that Russia "will not win".
We need your consent to load this rte-player contentWe use rte-player to manage extra content that can set cookies on your device and collect data about your activity. Please review their details and accept them to load the content.Manage Preferences
EU Commission chief Ursula von der Leyen also warned that despite opening talks with the United States on how to end the conflict, Mr Putin was not about to back down.
"Putin is trying harder than ever to win this war on the ground. His goal remains Ukraine's capitulation," she said.
She also called the war in Ukraine "the most central and consequential crisis for Europe's future".
Read more: The third year of the Ukraine war in facts and figures
Deal that 'suits' Russia
But as leaders of Ukraine's backers lined up to proclaim support and hail Kyiv's resistance, there was one notable absence: the United States.
Donald Trump's return to the White House has threatened broad western support for Ukraine as well as vital military and financial aid at a critical juncture.
His opening of talks with Mr Putin, a false claim that Ukraine "started" the war and verbal attacks on Mr Zelensky have triggered alarm across Europe.
The Ukrainian government has said it is in the "final stages" of a deal with the US to give the United States preferential access to rare minerals - one of the sources of disagreement that has exploded over the last week.
"There are almost no unreasonable demands anymore. Many details will be discussed later in another agreement," a source in the Ukrainian presidency told AFP separately.
The US has also urged Ukraine and Russia to back its plan to end the war, as the UN General Assembly prepared to vote on a US resolution marking the anniversary.
Russian officials have been buoyed by Mr Trump's outreach, sensing an opportunity to push their core demands: the roll-back of NATO's military presence in Europe, territorial concessions from Ukraine and the end of western military support to Kyiv.
Officials from Russia and the US are set to meet in Saudi Arabia tomorrow, a diplomatic source told AFP, a follow-up to talks between Secretary of State Marco Rubio and Russian Foreign Minister Sergei Lavrov last week.
"We will stop hostilities only when these negotiations produce a firm and sustainable result that suits the Russian Federation," Mr Lavrov said during a visit to Turkey.
On the streets of Moscow, there was support for a hardline approach.
"I would like peace. But of course, I am hoping for victory for Russia," Yevgenia, a 27-year-old civil servant, told AFP.
'You cannot be weak'
Meanwhile Mr Zelensky has repeated his call for security guarantees from Kyiv's backers to ensure Russia did not use any ceasefire to rearm and attack again at a later date.
With Mr Trump sceptical of continuing to support Ukraine, Europe has been left debating whether it can fill the void.
The European Union has announced a 16th round of sanctions aimed at curbing the Russian war effort in a move echoed by Britain, which levelled penalties against 100 entities.
Russia has been making steady gains across the front line in recent months, beating back outgunned Ukrainian forces at key sectors in eastern Ukraine.
The Russian defence ministry claimed to have captured the village of Topoli in the eastern Kharkiv region bordering Russia.
Further south, Tetiana Zhuravlova had finally made the decision to leave her home in the frontline village of Chernigivka in the Donetsk region, which the Kremlin already claims as part of Russia.
"There's been shelling everywhere here," the 47-year-old told AFP.
"I just want peace and quiet, for it all to finally stop, all this loss of life. People are leaving their homes, where they've lived their lives, they're leaving everything."
