President Volodymyr Zelensky told a conference on Ukraine's reconstruction that the required work was a "common task" of the democratic world.
Ukraine's infrastructure losses amount to more than US$100 billion, according to his prime minister.
NATO has formally begun the process of bringing Sweden and Finland into the alliance, with the members signing accession protocols in what its secretary-general called a "historic moment."
Ukraine's military said Russian forces are preparing new moves towards cities in the Donetsk region still controlled by Kyiv after taking control of Lysychansk, the latest city to fall in the Luhansk region.
Up to 60 million tons of grain could be trapped in Ukraine by the fall if the country continues to face blocked exports, Zelensky said.
