European leaders joined President Volodymyr Zelenskyy in Kyiv on Monday for official celebrations marking Ukraine’s Independence Day as Russia pushes on with its 4-year-old invasion of the country.

One of President Vladimir Putin’s key goals in starting a war with Russia’s neighbor in February 2022 was to place Kyiv in Moscow’s orbit. Ukrainians voted overwhelmingly for independence in 1991.

With no significant changes on the front line for months and no apparent progress after more than a year of U.S.-led peace efforts, the warring countries are locked in a spiral of escalating aerial attacks that are killing civilians and smashing infrastructure.