Complex sentence: Due to the Crimean crisis, on 17 March 2014 he was put on Canadian, EU and US sanction lists; his assets in these countries were frozen, and Aksyonov was banned from entering these countries.
Split into simpler sentences: Due to the Crimean crisis he was put on the Canadian, the EU and the US sanction lists, 17 March 2014. His assets in these countries were frozen, and Aksyonov was banned from entering these countries.