Ukrainian President Volodymyr Zelensky hailed Ukraine’s “absolute heroism” on Monday as the country marked the third anniversary of Moscow’s full-scale invasion and European leaders began arriving in Kyiv for a summit.

For Ukrainians, Feb. 24 was a day to remember, without major ceremony, what has been lost in the three years since Russia’s invasion.

Ukraine enters the fourth year of all-out war with Russia on Monday, unsure it can rely any longer on its staunchest ally the United States as its exhausted troops fight to hold their ground against unrelenting enemy advances.