Ukrainians honoured fallen loved ones on Friday and vowed to fight on to victory, while Russia said its forces were making battlefield gains in the east as its invasion entered a second year with no end in sight.
Meanwhile, the UN Security Council held a minute of silence on Friday to mark the first anniversary of the war, after Ukraine's Foreign Minister Dmytro Kuleba accused Russia of genocide against his country.
At a ceremony on Kyiv's St Sophia Square, President Volodymyr Zelenskiy bestowed medals on soldiers and the mother of one killed.
"We have become one family ... Ukrainians have sheltered Ukrainians, opened their homes and hearts to those who were forced to flee the war," he said in a televised address.
"We withstand all threats, shelling, cluster bombs, cruise missiles, kamikaze drones, blackouts and cold ... And we will do everything to gain victory this year."
In another development, he on Friday vowed to do everything to defeat Russia this year, as the first Western tanks arrived in Ukraine.
He said Ukraine needed to deepen cooperation with countries in Africa and Latin America to counter Russia's influence.
Zelenskiy was due to attend an online summit with US President Joe Biden and other leaders of the Group of Seven.
"I'll repeat today what I said one year ago as Russia invaded Ukraine," tweeted Biden. "A dictator bent on rebuilding an empire will never erase the people's love of liberty. Brutality will never grind down the will of the free. And Ukraine will never be a victory for Russia. Never."
For Ukrainians who have spent much of the year in bomb shelters and supporting the war effort any way they can, the anniversary meant reflection.
In Russia, where publicly criticising the war is punishable by long jail terms, the mood was muted.
Ukraine's blue and yellow colours lit up the Eiffel Tower, the Brandenburg Gate, the Empire State Building and the Sydney Opera House. They were painted on the street outside the Russian embassy in London.
There were no major public events to mark the anniversary in Russia, which set off fireworks on Thursday for the annual "Defenders of the Fatherland" holiday and held a pop concert on Wednesday attended by President Vladimir Putin.
Tens of thousands of Ukrainian civilians and soldiers on both sides are believed to have died since Putin ordered the invasion, saying it was necessary to protect Russia's security.
Moscow still occupies nearly a fifth of Ukraine, which it claims to have annexed.
UN chief Antonio Guterres said on Friday that the war brought "hell" to the Ukrainian people via "widespread death, destruction and displacement."
Russian troops have destroyed Ukrainian cities, set a third of the population to flight and left behind streets littered with corpses in towns they occupied and lost. Moscow denies war crimes.
Putin says he is battling the combined might of the West in what he now depicts as a fight for Russia's survival. Kyiv says there can be no peace until Russia withdraws.
Despite strong support for Ukraine in the West, big developing nations, above all China and India, have kept clear of imposing sanctions on Moscow. At a meeting of finance ministers of the G20 group, which includes Russia, host India made no mention of the conflict. Western countries pushed for a final communique recording opposition to the war.
They on Friday sought to bridge differences over how to deal with Russia as the West stepped up sanctions against Moscow.
Meanwhile, the US on Friday announced that it would impose additional sanctions on Russian individuals and companies over the invasion.
