Japan, this year's chair of the Group of Seven, expects Russia's invasion of Ukraine to dominate talks among the world's major advanced economies, said its top finance diplomat, Masato Kanda.

"Sanctions against Russia and support for Ukraine will be a top priority at G7 financial leaders meetings under Japan's chair," said Kanda, who will oversee G7 deputy-level talks on economic policy this year.

While Kanda underscored the importance of G7 unity in standing up to Russia, some analysts say there may be differences on sanctions, particularly among Europeans who are being forced to wean themselves off Russian energy supplies.